What should be my strategy for sure shot selection in UPSC prelims?(Archit Chandak, IPS 2018; AIR 184,)

This is perhaps my first answer related to CSE on a public platform.

First, let me give some background about myself. I have given two attempts for UPSC CSE, right after graduating from my alma mater - IIT Delhi. I went till the interview stage in my first attempt (2016). In my second attempt, I secured an AIR of 184!
Coming straightaway to the demand of this question which asks for a sure shot strategy for Prelims - I do believe THERE IS SUCH A STRATEGY.

Mains and interview can still be subjective and can become a hindrance for many talented and knowledgeable people. But with all humility at my disposal, I believe a smart strategy can make sure one secures reasonably well above cut off (+10), so if even somebody is working very hard and is not able to clear prelims, he/she needs to just tweak study habits a bit.
I have scored 138 marks in 2016 and 122 marks in 2017. I gave this attempt too (for rank improvement) and by various answer keys I am scoring 130–134 in 2018 Prelims. The aim of conveying my marks is to just ensure that you realise the strategy works. I had a mere 17 days for Prelims 2017 and had not really prepared a lot before the 2016 final results, which left me only dejected and depressed. Still, I did manage a handy 122, so I am very sure it does work. And I am hopeful it works for anybody who gets to read this. So let’s start with the main things (Point 5 is a must read) and then the useful hacks:

I hope nobody expects basics from me. We all know the sources and the various books to refer and we all know the importance of revision. Read diversely and in depth. I referred to 2–3 sources for one particular subject. It’s not a big deal once you cover your syllabus. The next source is completed in 1/4th of the time. Moreover, we tend to remember different things from different sources, so it always helps.
Importance of a peer group - I cannot really stress more on the importance of a good peer group for prelims (and the whole preparation as well). It can be a single person or a group of 3–4 like minded individuals. Just 40 days before prelims - we used to constantly ASK QUESTIONS on our Whatsapp group. And they can be weird questions too. It usually results in learning of 100s of facts/bits daily! It has helped me in directly answering 5–7 questions in Prelims!
TEST SERIES - I don’t think a person diligently doing 2–3 full test series of reputed institutes can score anything below cut off (if at all one does, it’s really a bad and unlucky day). I solved more than 50 test series papers ( Vision IAS, IASBaba 60 day, Vajiram ) in my 2016 attempt. I supplemented it by Unacademy daily 10 questions (Roman Sir) in my second attempt. It sounds huge but it’s not an ordeal when one loves doing it. A prelims test takes 1 hour to solve and 1 hour to evaluate (if it takes more, cut down), you can do 2 in a day and finish these tests in less than a month. How do these test series help you ?

Builds your exam temperament (absolutely necessary for prelims)
However and whatever you study, you need to make intelligent guesses in the exam. The test series work like magic - they mould you to think in such a manner that your intelligent guess work pays off in 6/10 questions.
It’s basic human nature to remember things one has done wrong. I used to consider doing the same question wrong a second time, a crime!

Remember things - Read consciously: Many people who come up to me for advice have a common refrain- NCERTs? Done them. Standard books ? Done them too. I just ask them some questions from the basic NCERT books and when they can’t answer, I have a hearty laugh and advise them to do those again properly! (That’s the only way one realises importance of reading thoroughly!) If you can’t answer it - NO, IT’S NOT DONE. Be ruthless. Do everything which you have in front of you so well that you are able to recall it in the exam seeing the options. So whenever you read, keep talking to yourself, ask yourself questions and answer them- it really helps in remembering things. Reading anything for the sake of it is a pure waste of time.
How to do GUESS WORK IN THE EXAM ? The most important thing which one should take away from this answer. It is humanly impossible to know everything under the sun but it is not impossible to select the right answer when you have options in front of you. I will share some examples for you:

Now anybody with a decent understanding of modern history knows that statement 1 is absolutely correct (very easy if you follow points 1–4 above). Another thing, if you have now eliminated option b and d, you must answer this question ( 2 options eliminated - go for it ) Now coming to the 2nd statement - I had no clue of it. But now think this way - Why will this statement be wrong ? Only in two cases - either it is not in coherence with general scheme of things (what really happened in Santhal rebellion) or the examiner creates this option out of thin air. The first case is ruled out as we know that Britishers followed a pacifist policy after the rebellion so it makes sense. There’s a negligible probability that somebody would create this option. ( It also may happen but I assure you, this strategy does work in 7/10 times during the whole paper). I very confidently marked C and it was indeed the correct option. Learning : Find reasons for the statements to be wrong. Let us take another example:

Now, anybody with a decent reading of environment knows option b is Global warming, option c is oceanic acidification. (Again, only two options left - MUST ATTEMPT!). Now see the question. It asks for carbon fertilization. What can be fertilisation - increased plant growth OR adaptation ? Basic general awareness tells us that option a is correct- indeed the correct answer! Learning: Atleast 3 questions have answers hidden in the question itself! Another one:

Most of us don’t know a thing or two about Prosopis Juliflora ( It’s actually Seemai Karuvelam - which we do study in current issues but nobody remembers the scientific name! )
Now, look at the question and then the options - often mentioned in news ? Which option suits this statement the most ? :) Yes, it’s option b. See, it may seem futile when one overthinks - why can’t it be a ? It can be mentioned in news too. The point is, this guess work naturally comes to you after multiple test series. Your aim is to guess the most relevant option (if you don’t know that question and are a person who wants to maximise your attempt). Learning: Read every bit of question carefully.

Now, see this. It was actually a very tough question. But again, multiple tests help you here. It gives you confidence that you are thinking correctly. Logic which one can easily apply here- Option 2 is definitely correct (no organisation creates binding obligations - it’s very rare). Now see the name - Global Alliance for Climate Smart Agriculture - It shows it’s a recent body. See option 3 - India’s instrumental role. If you have done Shankar for environment thoroughly, all your test series thoroughly, you can be reasonably confident that one would actually have bumped into GACSA in some or the other test (if India did play an instrumental role) Nothing of that sort happened, a never heard body. So 3 is wrong, left with only b. Mark it and secure your two marks! Learning: Be confident of what you have read.

This is from CSE 2016. Now come back to rule 1. Find reasons for these two statements to be wrong We all know how economically advanced Vijayanagara kingdom was - so this does not violate the general scheme of things. What are other options ? - Maybe there is no industries tax, maybe tax rate is uniform for land (highly improbable). Would somebody just create the option of industries tax for the sake of this question ? 90% chances - no. It really does seem C and it actually is. Learning: remember your rules!

Now see this from 2016. You need to be confident about your strategy and preparation. We all know the functions of IMF. It is extremely rare for IMF to be associated with The Economics of Ecosystems and Biodiversity. ( It could have been a possibility had it been World Bank, knowing the vast project areas WB is associated with). You can very safely assume 1 to be wrong. 2 and 3 statements are so generic in nature that no sane person would regard them as wrong. Answer is indeed c. Learning: Make good use of elimination strategy.

Please don’t be fooled into believing that this will work always. But my experience with 3 prelims and 125+ scores in all of them shows it works 7/10 times, which is highly advantageous. It gives you an adavntage of 10–12 marks easily and can help any serious candidate (even if he is near cut off) clear this stage smoothly. Some other important hacks:

Extreme options have a minuscule possibility of being correct. If you have words like any, only, drastically reduce, rapidly increased, THINK TWICE before marking those options as correct. There are just so many examples for this in the past 4–5 year papers! Please go through them.
UPSC loves to play with numbers - dates (Trade Facilitation question - 2017), amount (NIIF, Paris Climate 100 Billion $ was shown as 1000 Billion $ ). So be doubly wary of such numbers.
Expect MINIMUM 3 QUESTIONS on environmental bodies. Shankar won’t help you here. You need to go through websites of IUCN, WWF, GCF, UNEP, UNFCCC etc There’s an amazing website I bumped into - Search Initiatives - Nobody really knows about this! But just go through it- It’s an amazing ONE STOP SOURCE for various Environmental bodies and their HQs, associated members etc. Everything arranged in proper fashion. Go through it!
Try to maximise attempt. I have always attempted 90+ and it has helped me. Try this in test series and see if you are comfortable with this strategy first. Do not consider yourself to be in the race till you reach the magic figure of 70 - 20 - 10 ( Correct - Wrong - Left ). This is an ideal attempt, enough to clear any possible cut off! I have always strived to achieve this. This may not work for people who rely on exceptional accuracy. But do try this in test series and see if it works for you.
VAJIRAM Art and Culture book - States Book is extremely essential. It’s colourful, really fun to read too. We get to know so much about our country and culture! Read it multiple times and remember things of different states ( I could do all questions related to states - Sujani embroidery, Upada Jamdani , Chapchar Kut- questions of 2018 Prelims from here)
Current Affairs of JUNE - JUNE period (12 months) does not work. Please realise this. If you are a first attempter, do at least past 20 months of current affairs (only from prelims point of view). It’s not an easy task I know, but almost all questions in 2018 were from current issues before one year. If you want to clear this stage, make no mistake, take no chances.For UPSC 2020 This is what you need Click here

Two years of Current Affairs.Complete Coverage of Newspaper,Vision Current Affairs magazine,PIB,Survey and Budget.Click here

Guess work works only when you have studied and revised everything properly. Don’t supplant your preparation by that, just let it supplement your preparation. Note making is important but more important is to get the thing in your head, so read consciously and keep asking yourselves questions. Be inquisitive. Don’t hesitate in reading and learning more. As upcoming civil servants, we are expected to know of various current issues and happenings.
Develop exam temperament. I really cannot stress more on this! This is absolutely essential and sadly one of the main reasons why people studying very hard too, find it difficult to clear prelims. Only multiple tests can help build the exam temperament.
Read, every question slowly and properly in the exam. All my friends (myself included) have a common refrain - if we even avoid the basic mistakes (reading incorrect as correct, not removing extreme options, overthinking about some statements etc.) during those 2 hours - we can increase our marks by more than 10!

I hope this will help. Please go through this answer multiple times so that you make it a habit to implement anything you like from it.
Civil Services Exam is indeed very tough, I know, but not insurmountable. It’s a perfectly doable exam when one has the right underlying motivation to become a civil servant, a sound strategy and is sincere enough in the hard (and smart!) work they are doing. All the very best!