The basic manner I do it in is thus:
I have a good memory - I will remember key things close friends/family like, and what they do and don't have in terms of items or experiences related to it. I look around a little bit, and it usually hits me in time to actually get it.
As an example, last year I bought my S.O. Frostmourne. It is a very large, beautifully crafted, geeky sword, and only one company makes the replicas. I like giving people surprising gifts, so it's actually fun for me.