Been lots of discussions about ST PADDs about lately. They are easy to make with just a few layers of wood and lots of filler-primer. Finding the right color paint (an issue I am currently having) takes a bit more time, but it is a good holiday project.
River song diary (external stuff only) would be a quick project too. Get an old book, some pva, some thin cardboard (cereal box) and check out some youtube videos on modding a book cover with a design. It would take the most time to cut out the design and wait for glue to dry, but you can get good results quickly.
Just throwing stuff out there for ya.