Not necessarily frugal advice, but if somebody is a bit of an expert or even hobbyist in something and you are not, don't buy them something in that area unless it's something specific they have told you they like or that they want.

Eg, if they like chocolate, don't just go buy Cadbury. No offence to Cadbury and Cadbury lovers, it's just an example that some people might love Cadbury and eat nothing else, and others might hate it. You might go out and spend $X on a fancy brand, when that's one that they hate, and actually prefer a cheaper one.

Sure it's the thought that counts. But there's levels of thought, and shallow thought can be borderline offensive.

Eg, I'd way prefer some of the fantastic, unique and personal ideas here than get an expensive gift of a bottle of X, that I've probably already tried, and have settled on what I like.