I can't address some of the more technical aspects of settings and such, but one technique that works quite well is to find a torrent with many files (freeleech or not) and then just select a few of them for download--perhaps 10% of the total volume). Those will often download quickly, and then as other users are clawing at the system to get the whole content, many will be directed to me for the 10% that I have.. This works best when there are only a few seeders vs. many leechers, such as in a newly uploaded (or newly freeleeched) torrent.
It's not unusual to get, over time, a ratio of 30-50 for such a torrent, which I keep seeding even if I'm not interested in the content. For example, as I type this, there's a newly uploaded torrent called "Tom fucks a nerd," that has only one seeder (likely the uploader) and so far three leechers (likely to be more soon). There are 296 files in this torrent, and if I set my client to get just 30 of them, my ratio on that torrent will be huge within a few days.
The only potential drawback to this approach is that the system will count this torrent against your "maximum number of simultaneous downloads" limit since you haven't downloaded all of the material. If that's an issue in your case, you can delete the torrent from your system after a couple of weeks after bumping up your ratio,