Wing tattoos are very popular, they look really good. A tip: If you're going for wing tattoos, get them so they cover up your whole back. Small wing tattoos just don't work, they look out of proportion with your body. The scar idea is a good one, I've seen that a couple of times (if you mean an actually professional done scar, not a tattoo that looks like a scar, but I've seen both). Make sure you do some VERY good research when searching for the right person. Theres very few people capable of doing that sort of work correctly.