Okay, fine. A few elements that tend to be popular–but I won’t guarantee anything–are:
- Cute or child versions of characters (known as “chibi” if you speak anime)
- Cats of all sizes and species
- Anything with wings (Seriously. When I ran a science fiction con art show, stuff with wings, including cats, sold amazingly well.)
- Sensual, rather than sexual, pictures. Go for the tease rather than the full monty.
- Half-naked men. Anything a high school girl can show her mother, but that still appeals to her…baser instincts. (I can’t tell you how many girls come back to me next year and say “I have your picture of So-and-so on the wall right above my bed!”)
- In recent years, anything with an angel or devil theme
- Characters from anime currently playing on Adult Swim or Toonami, and popular video games
- Pictures with lots of detail. People equate “detail” with “good art” although every artist knows that isn’t necessarily the case.
And a note about fan art and the pairing phenomenon. Pictures of specific romantic pairings don’t sell as well as you’d think. Why? Because they limit the number of buyers to fans of that couple.
But a picture with the same two characters in it, not interacting in a romantic way, sells more. This is because fans of that pairing read the pairing into it, and the others see it simply as a picture of the two characters. If you’re a Hobby Artist who’s a fanatic shipper and want to draw your pairings, go for it. If you’re a Pro Artist and want to sell more, consider not boarding the ships.