Got a pack of the Oblique Strategies cards by Brian Eno and Peter Schmidt. I've known about them for a while but was reminded of them recently after seeing this pic of David Bowie's deck.
I was so happy to discover you can still get these from Brian Eno's site. They are the perfect tool for overcoming creative block and reinvigorating any project. The set contains over 100 (103 in my pack) of simple yet perfect nudges to open your mind - far more useful than the many convoluted 'frameworks' that consultancies like to flog.