I think promoting yourself through the internet, marketplaces, and advertising would get you started, personally your drawings just sell themselves, they are so GREAT!! I am in awe of you, you are so lucky to be so talented, but I sure know a lot of hard work and time goes into them.

Good luck, I hope your business takes off, your talent is too good to be wasted, and I am certain you could make a nice little living off them too, we have guys who do self portraits at the marketplace for 20 dollars a time.

BEST OF LUCK!!