My last writing tip was to select some old movies for a re-write. Well, I've come up with another- grab a list of movies (go to imdb and do a search for an actor or director) and then try to come up with a plot based on only the movie title. This will only work if you don't have any idea what the film is about, all you have to work with is the title. It's a pretty neat way to get the creative juices flowing and, as well as being a way to while away the time when you can't write, it's also a great way to come up with some new stories.
At the moment I'm working through a list of movies by the likes of Roger Corman and Fred Olen Ray because low-budget trashy sci-fi and horror appeals to me. Movies with titles like "Captain Nuke and the Bomber Boys" are also pretty fun to try and plot.