[Scandia]

I have been in two classes where we liked the professor so much that we gave them beer-related gifts. In one class, we purchased a six-pack of Guinness bottled beer. For another one, we purchased an engraved stein with an inscription in German (since this was the subject matter).

I have only given thank-you notes before. However, I think that if they have major hobbies that they enjoy, you can give them something related to this. Otherwise, perhaps a nice pen or mug. Or flowers if it is a female recommender you have established rapport with.