Without donation and new downloads, you should try to seed what you've got. When I've made my previous answer, I had promoted some torrents you were the only seed, that should saturate your internet connection for some time. BTW, two of them got now many leecher but are not seed …
Other options are:
Vote categories, you have downloaded many torrents and that should bring you quite a number of SBP. It takes some time though. Upload pictures to descriptions with less than 10 pictures, yet. Upload an own torrent for something still missing here