For me a noticeboard exposing al sorts of stuff and ideas is a great source of inspiration.
This board is a small exhibition of materials – almost a collage in itself. But it could be a collection of anything. The little items you collect, bits and pieces of this and that, old stamps, etc. When you gather your materials at a board – they don´t flow all over the place (hopefully).
Sometimes, when I don´t know where to start, it can be very helpfull just to organize the stuff in the workshop. You simply tidy up the place, arrange tools and materials so you know where to find it, and suddenly in this clearing process you find something that kicks you off. That usually works for me!
Another hot spot for inspiration is browsing all my notebooks and art-journals. It hardly ever fails, I always end up totally carried away by ideas and projects I´d like to start. Right now the only source lacking is time! Ever heard that before?