Here are some tips for you:
It’s all about speed!
The faster you can attempt questions, the better.
Accuracy matters too!
Try to strike a balance between speed & accuracy. Just because there is negative marking, don’t go marking random answers! Try to attempt questions from all the five sections as some colleges ask for sectional cut-off from each section including General Knowledge Section.
There’s nothing like practice!
It would be ideal if you join a test series of renowned coaching centres like IMS, Career Launcher, TIME etc. or practice free online mock tests.
Get your basics clear!
Before you move on to practicing questions from big, fat book, it’s important to get your basics (for quantitative especially) cleared. For this, you have to go back to your humble NCERT textbooks. After you’re through with that, you can graduate to books from Pearson for both Quantitative and Verbal, R.S Aggarwal for Verbal as well as Logical Reasoning, Wren & Martin for your English.