-- uses technology of interest to potential employers
-- he's (at least somewhat) interested in
-- not be too ambitious (start by trying to solve a small problem, especially one you know something about, rather than trying to re-invent the world)
-- that might have commercial possibilities, but don't worry too much about that
-- that someone else might have done something similar --> but this doesn't matter because the primary reason is to develop some expertise yourself, and do it with your own twist

Don't give up, but be realistic

Tony