I agree with all of the suggestions so far, especially the quick project for almost instant gratification. I keep one or two projects out, but if I have more than that going I put them in my waiting-to-be-worked-on drawer; if I see too many out at one time, I can get discouraged.
Something else I like to do to get my creative juices going again is to visit my local quilt shops - getting up close and personal with so many beautiful, finished quilts seems to renew my interest. Works better for me than looking at pictures online, not sure why.