[oneepic]

It's a huge space, so I wouldn't say it's easy. Also several ideas will just not be interesting to you at first, and many others will only be revealed as uninteresting after a while (ie you hit a problem you aren't interested in solving).

One idea might be to learn something new, if you don't have a project. Think about a textbook or a class, or online texts, or just some interesting popsci at the local bookstore/library for example. any might work depending on your style.