Fan-fic, the never to be published kind, allows me to fantasize and work on world-building with a pre-established world and pre-created, well flushed out characters. At times I'll take a character and go hypothetical internet shopping/browsing with them and see how they would react. It helps in my character-building skills. I also allow myself to have a couple tangent works, when I have a main work, to write whenever I get stuck on one, I can switch to another for a bit. Another thing I've done is go looking at floorplans online with certain characters/ situations in mind.