I also do it the way Rich does it.
If I need something fancy, I cut the shape out of flat stock with a jewelers saw and solder it to a bar of steel, then chisel it. I have done custom side plates for new builders too, because they want to make their own rifle but are not experienced enough to make such a plate.
I cut and chisel nice ones out and se4ll them for about $50 to $125 depending on how fancy they want them. It makes for a classy rifle or pistol that has something unique on it, and still lets them build it themselves.
Here are a few examples.