still working out the deets, but probably along the lines of

$5 for sketches
$10 for clean lines
$15 for clean lines + flat color
$20 for clean lines + flat color + shading
$30 for ^above + a background
$40 for something like Antler & Pelt

I'd draw... anything really. All digital. Your characters, your favorite characters, your favorite pairings, your favorite pairings doing the nasty... Idc.