To show your appreciation for your father-in-law this Christmas, consider gifting him something thoughtful and personal. A personalized photo album or engraved watch can be meaningful and lasting mementos. Alternatively, you could arrange a special activity like a fishing trip or a day out to a sporting event he enjoys. If your father-in-law has a sense of humor, consider a gag gift like a funny t-shirt or novelty item. Remember to take his interests and personality into account when choosing a gift to show your appreciation for him as a part of your family.