1) learn how to draw. To do so read sticky on /ic/ (it's 4chan board). Then read books mentioned in sticky, do exercises and so on…
2) draw disgusting fetishes like scat, watersports, necrophilia, loli (or even furry if you're not disgusted) and post them everywhere.
More disgusting fetish = less artists are doing this = more commissions (and $) for you
3) Tell everyone you're doing commissions. Set high prices, because dumb people think that expensive = good.