While I am a much better cartographer than an illustrator, when I can't afford to hire a proper artist, I end up doing the work myself - I'm hit or miss with illustrations, but I'm not too bad. Here are two illustrations I just created today, using movie poster art for reference for my upcoming Way of the Samurai (PFRPG/Kaidan) supplement.
I used Xara Xtreme Pro 4 to create them, the same application I use to create my maps.
The first one is the Nitojutsu Sensei (two swords master Samurai archetype):
The second one is the Onmyoji (origami wizard archetype):
I'll need to make a few more.