I'd probably do much what I already do, but more of some things and less of others, depending on the day.
I got into soap making about a year ago, so I'd do more with that, because I enjoy making the physical things and it's a great creative outlet.
I'm a web developer by trade, and work has sucked a lot of the enjoyment out of that, but if I could do my own stuff, on my own, I'd probably get back into it and make stuff to solve various problems that I've run into.
I'd also write my blogs more. I have two right now -- one for tech stuff, the other for health stuff -- and would expand on those two. The health one, especially, is for helping other women with PCOS, so I'd love to continue that one. The tech one is my more "professional" one, so it's more for projects and things that relate to being in the tech industry. It'd probably change a little since it wouldn't be a job anymore, but would still have various musings about being a woman in tech stuff and whatnot.
If I could get the space, I'd love to get back into pottery, too. I always loved pottery growing up and have dreamed of getting back to the throwing wheel and making stuff like that. I'd go bonkers if I could get my hands on a good stone kick-powered throwing wheel, a kiln, and a place to keep them. (I've already fantasized how my pottery and soap making could augment each other, including making mugs for shave soap kits.)