English grammar is one the most complicated subject in a students life.so from this it is important to understand the psychology behind the whole scenario, why the students fear from grammar and why they dont have likings towards it.
when I was a student I also used to fear from it. but before the board of 10th I thought to throw out my weakness of grammar .i started the practice of grammar and then results were in my favour .so I will tell you in this that how to basically handle a grammar book.
ADVICES-before taking any grammar book ask to your teacher and take advice from him before buying it.you can also use other sources like advices from internet advices from previous year students these advices might help you in buying a grammar book.
secondly once you have bought a grammar book you should have one clear and definite aim in your life and that is just practice.practice it seriously and you will get more than what you would have thought.
thirdly -now I will tell you how to use a grammar book to the fullest.first take any lesson read each and everything given about the topics. then go for practice and keep on revising it .soon you will master it.
one of my personal example is that by using an following above tips with full devotion I scored full marks in grammar in my 10th exams