Honestly, I think the idea of a gift card to the LHS is a great idea... They may not expect it, nor do they train for financial gain. But who in this hobby couldn't use a gift cert to their LHS? Like others above stated... Make sure that you also stick around the club and become a good standing member. That is probably the most important thing to a club.

I have not started my training nor have I even talked to a club, but once I do I think I will give a LHS gift cert to my trainer (if I need one that is) to show my appreciation.