I agree with RCKen in a lot of ways. As far as getting something for your instructor, that is completely up to you. Most instructors love it when their students solo and move on to outfly them. My main goal is to have my students be better pilots than I am. It's a never ending goal that can drive you nuts but it makes for great fun after the solo.

I did give my instructor a gift cert. from the LHS. I was there when he got it and it made his day. He then told me it was really not needed and I should have spent the money on myself. It's my nature to show my appreciation in any way I can think of and at the time I felt this was best.