How about:
1. Grafitti? Make a collection of images of various types of grafitti locally, if you have any. It can be remarkably successful as I based my RPS Fellowship on grafitti close-up abstracts.
2. Buildings? Especially modern buildings look good when details of them are cropped to square format. Very geometrical abstracts is the idea, interacting with the corners and edges of your square crop.
3. Graveyards/cemeteries? At this time of year many of the plants and bushes are out, and some of the older ones can be quite overgrown. Try to capture a "mood" with wider views, crops, and details. Lichens on tombstone inscriptions, sad little floral arrangements, weathered stones, etc etc, all add to the feel of the place.
4. With these and other projects you might try to make a book of the best ones using an on-line publisher like Blurb or Lulu. There is discipline in selecting and editing work to go in these that will improve your photography no end. You can even try a home-made book by printing your work and sewing the sheets together. Even cheaper perhaps, althou small Blurb books aren't too bad.
