How to deliver thank you letter and gift to the professor who wrote letter of recommendation for me
Another important point to mention is that you should make sure that your gift is not too generous. Some universities have rules in place against personal gifts that exceed a certain monetary value (I think that in my university it's $100 or so). Anything more than that, and the professor will have to (a) report the gift to HR and (b) most likely won't get to keep it. These rules are in place to prevent academic misconduct, so I would really make sure that your idea of small fits university guidelines on what small means.