It’s never too late to make your concepts clear…if you have a strong hold on the basics of the subject your half jobe is done.. Second thing is solve as many as MCQs you can…go for the test series provided by the coaching institutes…make your self adapted to solving the full fleged question paper in given time…don’t hesitate in giving tests and don’t leave it for next time…this can be the biggest mistake on your part.
Third and most importantly I feel don’t ever let yourself feel demotivated at any point of your preparation…marks are mere numbers u can change them whenever u want…so don’t feel low by your tests marks bcoz there is always scope for improvement…
And TAKE BREAKS SO U DON’T QUIT.