Ah, great question! I love to...
...Design houses and other kinds of buildings, either with graph paper or in Illustrator. When I get a design I really love, I'll even landscape and furnish it, right down to designing the textiles on the furniture. I've done this ever since I was about 12. Like George Costanza, "I've always wanted to pretend to be an architect."
...Make stuff out of garage sale items and castoffs -- like padded footstools made from old wineboxes or cheeseboxes, fancy frames made by gluing heavy lace trim to a 29-cent Goodwill frame and then painting and antiquing it... I really enjoy taking things that people think are useless and making them live again!
...Make jewelry -- mostly offloom needleweaving with beads, but also wirework and plain old stringing. Oh, and ddcats -- I made a rosary once, too, for my father. He has a very, very old wooden cross banded in silver that was given to his mother by an elderly neighbor when she was a child, which would have been in the late 1800s... and the cross looks exactly like the ones given out some decades earlier by a priest (French, I think) who ministered to certain American Indian tribes. My father thinks it may actually be one of those crosses, and he wished he had a rosary like the one the priest has in an old tintype... so I some carved wooden beads that looked right and used fine silver wire to make the tiny wrapped loops and put the whole thing together for him. It was such fun to make something with a special meaning like that.
...Play guitar and piano, sing my heart out whenever I'm in private, and write songs now and then.
...Read and read and read until I can't keep my eyes open anymore.
...Dance. Not well,
mind you, but when nobody's around and I'm feeling good and I have the right kind of shoes on, I love to do a little tap, a little softshoe... now and then a little Bob Fosse, though he'd pirouette in his grave if he saw someone my size trying to strike one of his poses!