I would like to complete graga's answer a bit. From my experience, ways of earning depend on not only skills but also your experience and knowledge of the sphere you're intended to enter. That could be anything, and everyone chooses what they like the most.
If you'd ask me what I choose, I'll vote for online gambling. For me, that's a good combination of business and pleasure. Long enough I played with low-medium stakes, and now planning to try casinos for high stakes — http://gamerlimit.com/zodiac-casino-pla ... gh-stakes/
. They require a lot of experience, knowledge and applying different techniques, strategies. But I'm experienced enough, so I think I can handle this. If you've got interested, have a look and try. Maybe you'll like that.