Steve Tippins Ph.D. warns against expensive gifts to dissertation committee members, which can look like bribery or violate IRB rules. Instead, give modest tokens like engraved pens or a bound copy of your dissertation. Know each person's preferences first.
Along with thanking committee members, it is a practice that some people partake in, in gifts to their committee members. Gifts to people like this can be problematic. You don't want the gift to be too big, like don't give them a car. They can't accept something like that. It needs to be a gift that is meaningful but isn't overly expensive. When you did your research, the IRB wouldn't allow you to give participants $4,000 to give you answers. So you don't want to be doing that for your committee members either because then it looks like the committee members— or it could be implied that the committee members were paid off to give you your degree. But giving them something— a pen, or with their name on it, or something engraved saying "thank you"— some people give copies of dissertations, a bound copy of the dissertation, to committee members. I would check in their office if you get to see their office. Do they collect these and keep them? Great, then they want them. Other people may not want them. Understand who your committee members are and what they may want.
