Qualitative analysis is viewed as one of the most difficult chapters of inorganic chemistry because it requires sheer cramming with little or rather no logic. This is the perception of most JEE aspirants. But my view is a bit different.
If you study from a good source(which has been mentioned below) then I don't think that this chapter is that difficult as a JEE aspirant feels.
Here are a few tips :
1.) Prepare this chapter by "writing" the reactions on a notebook. You might feel that if you just read it once, then you are done but the case is different. An average JEE aspirant doesn't have that high IQ level. And it has been scientifically proved that we remember things better if we write them once. So carry pen and paper with you when you study this chapter.
2.) A good and reliable study material with a simple language is the best. For example - I used FIITJEE packages parallel to a book called Vogel's qualitative analysis. It's a good book but it is not meant for JEE. You have to study only about 15% of that book for JEE. You might like to try something else. But the above 2 must be sufficient. Note that instead of FIITJEE packages, you might have a different package. But don't worry, all are more or less the same.
3.) Solve a number of problems especially the past year problems. Don't miss a single problem from at least past 25 years. They repeat the questions from this chapter.
4.) In the end, the most important thing is revision. As I have already mentioned in my inorganic chemistry post, all the chapters of inorganic chemistry (qualitative analysis included) require intense revision. You are highly likely to forget everything you did if you do not revise say once a week.