Oh, I also participate in the @yourluckyphotos tag drawing and the @photocontests tags as well. It gets me a little more exposure as well as tiny upvotes. As you win contests in photocontests they will up the level of your vote, though I think their system is overtaxed and their SP can't handle the amount of votes they give out because mine are still worth '0.00', which isn't actually 0 but kind of close enough.

Also, you can resteem your posts for free by going to the address bar when you are on your post and replacing the 'https://' with 're'. I don't know how effective that is but it is free. I do donate a few cents to it every once in a while but it is not mandatory.