I've gone minimalist, to go with my minimal skills in Paint. The photos I used before were the best I could do at the time, but they were never quite right. These are better, I think - and hopefully more eyecatching! (I think I may have overdone the red for Raven's Heirs!).
So they're now appearing down the sidebar - Quarter Day, Raven's Heirs and Like Father, Like Daughter. I've left Ice Magic alone, since 207 people have downloaded it with the cover it already has, and it's free. I'm hoping that people will give me real money for the others!