How do I make my art worth selling?

Hey all, got a broad, overarching, difficult question for all of you.

How do I make my art worth selling?

See, various factors are conspiring to make me ambitious that my work might actually be worth money...someday. Right now I'm not confident enough in my work to ask for money; everyone I know that takes commissions has an established style and/or extremely high quality of product. I...do not have these qualities. Either of them.

Now the first obvious fix is practice, yes, I know. But that's not entirely what I'm asking. What I want to know more, I suppose, is what are people willing to spend money on? Is there a particular medium, style, etc. that's (reliably) in demand? What should I focus my efforts on practicing? Or should I keep my generalist attitude and just try to hone whatever I'm most comfortable with? 

Alternately, what's a good way to break in to/start monetizing my work? Small, cheap commissions (sketches, headshots, etc) would be my best guess but I'm just not sure. It all begs the question of how do I show others (and prove to myself too, I guess) that my art is worth something more than a comment or a fave?

Thanks for the input in advance, I'm going to leave this one up for a while to see what comes my way. Until next time.