Let me introduce myself here first, I am Bharat chandani presently working with Directorate of Enforcement, Indore. I have cleared SSC 2012 with AIR 768, IBPS PO 2012 got IDBI Bank (didn't join due to SSC) Cleared UPSC Prelims 2011, CAT 2012 98.3 percentile, qualified RBI Grade 'B'Mains in 2013 and 2014 but couldn't make it through interview and now qualified SIDBI Mains. Guess that makes me qualified enough to speak on this platform about a few prepration strategies.
For beginners : yes taking a coaching class would be a good idea also regular solving of material is very Important. But what about retentivity, for that I'd say start teaching someone may be a kid of 6th to 10th class or someone of your own age preparing for competitive exams. Teaching Maths would improve your quantitative and reasoning skills, teaching science and so. science will improve the GS even GA Portion, and English would improve verbal ability. Also teaching would improve your conceptual understanding of the topic, you wont have to mug up GA from lucent or look out for short tricks for Quants. I myself had tought home tutions during my college days and then worked as a faculty at Career Launcher during my early career.
Talking about individual subjects :
Verbal ability : Yes it is very important to have a good Vocab for that I'd suggest you people to read Word power made easy by Norman Lewis, It is the best book for improving your vocab. It helps in Vocab related questions and Reading Comprehensions. For grammar here is a link
http://www.bankking.in/uploads/bankking-books/2015-07-27_093322_100_rules_of_grammar.pdf I'd suggest mug up these rules and see the difference in you. RC would come only after reading practice, reading any news paper, magazines of your choice and understanding the main idea of the article would suffice. Also home teaching english to kids help a lot in RC's.
Selective study is very important in English once you have prepared, We are here to crack an exam not to become Shakespeare or wordsworth, hence I'd rather suggest do the needful, for any given exam first look at the english section of previous year papers, look at the kind of questions asked in the paper and practice only those questions.
Quantitative Ability : Good Coaching or may be a personal mentor is important here. But the best way to revise your concepts is teach someone, like I said earlier. Once you are prepared, again it becomes very important to look at the Quant section of previous year papers of the exam you are giving and then practicing only those topics and kind of questions which have appeared in the exam.
Same goes for Reasoning. Apart from the above mentioned solving puzzles and inculcating a habit of playing reasoning related games would always help you in improving your reasoning abilities.
General awareness : For beginners a strict no to Lucent, Lucent helps in revision not preparation. Instead start with Sci and So Sci books of 6th to 10th or even till 12th. Here also teaching a kid would help drastically. I remember I was able to clear GS paper of UPSC Prelims 2011 only because I use to teach kids in my college. Though I was never a UPSC aspirant, I took coaching for CAT in my college days. Current topics can be done by regularly keeping up with a good English or Hindi news paper. Also Banker Adda's GK capsule's are very good for revision purpose.
Also following a regular routine for studies is very important. Dont spend quantity time while studying but spend quality time with your studies. For any further queries you may leave your comments in the comments section and those who belong to Indore can even meet me at my address I can help and mentor them for preparations.
Regards
Bharat