While solving problems based on determinants, you should keep few points in mind as:
a) Try to reduce the value of elements as much possible given in the determinants. Try to bring them equivalent to 1.
b) Before applying operation like adding, subtracting, multiplication or divisions among the rows and columns, make sure that the on applying the desired result is achieved or your elements will be simplified.
c) Make sure all the calculations performed by you are accurate and after solving one step recheck it so that if there is any error, it will be rectify immediately.
d) At last, practice is the key to success in mathematics. You should practice more and more questions based on determinants. It will help you in solving questions