Dear Ayush
practice problems from a good book and you must do the previous years questions.
In the exam hall after getting the paper first 5-7 minutes read the whole paper. this will give you rough idea about the questions to be attempted. 
Dont try to do the complete paper rather try to do the questions correctly in which you are confident, this will reduce negative marking. make some targets that I have to these number of questions in this much time. Students generally try to attempt the whole paper and make mistakes in hastle.
Do only those questions in first attempt in which you are very much sure and which are not lengthy. attempt these questions in the 2nd attempt if time permits.
 
All the best.                                                           
AKASH GOYAL
AskiitiansExpert-IITD
 
Please feel free to post as many doubts on our discussion forum as you can. We are all IITians and here to help you in your IIT JEE preparation.
Win exciting gifts by answering the questions on Discussion Forum. So help discuss any query on askiitians forum and become an Elite Expert League askiitian. 
Now you score 5+15 POINTS by uploading your Pic and Downloading the Askiitians Toolbar  respectively : Click here to download the toolbar..