That kind of person is the primary targe of my book, first off, so I would suggest they pick it up. They'll get a lot out of it.
Second, I would tell them to dig into what are the things they really don't want out of work, the things they do want, and then set some tangible goals that are the product of those two previous conditions (in that order). Ambition Mapping walks somebody through this process.
Outside of that, I would tell them to focus on learning skills that help them see tangible, visible progress towards the achievement of their newly-set goals.
Here are some examples:
Whatever you choose, the point is to choose something that you can see progress towards achieving that thing. This helps you build up self-efficacy. Self-efficacy is essentially your ability to see yourself accomplishing those goals on which you focus.
You have to build up this basic sense of self-efficacy before you go out and "find yourself," or anything like that. So the best way to do that is to build up self-efficacy on skills and projects that will last you your entire life.