Picture frames are always good. I know I have pictures all over. When I first moved out (years ago) my Uncle made me a shelf to hang on the wall for me to hold figurines that I collected. That was really cool too and I loved it because he made it. What things do they have in common? Maybe you could base their gift off of something that they both like.
I like ZG's idea. Many years ago, my brother made me a book shelf for my birthday. He built it, stained it, varnished it. In the wood, he inlaid a little 1" X 1" metal plaque of the month of Feb for that year. It was sweet and I have it to this very day.
Maybe a shelf or two to hang on the wall for wedding and other family pictures to sit on. Maybe make the frames instead of a shelf. Maybe a couple of Adirondack chairs for the patio.
There's nothing I treasure more than a wonderful home made gift.