A couple of years ago on another forum Virgil Suarez suggested an exercise: make a diorama that fits onto the lid of a peanut butter container (no scale or subject restrictions). It's a way of building something quickly and compressing an idea into a small space. It has taken off in a formal way in some competitions. I don't know if it was shared on this forum or not, but I recommend it as a fun thing to do. If you have built one, please share.
The variety was amazing and so was the imagination in each of them.
This is mine, a kerb from Cambridge MA:
