I don't know if it's been mentioned previously or not, but...one thing that concerns me as a downloader (I don't upload torrents to trackers) is the ratio - I have no problems leaving stuff going to help seed to build a ratio, but keeping a ratio might be difficult for people like me, who have a monthly bandwidth cap and whose ISP may either cut them off or bill them up the backside for additional data per month. This is one reason I am very wary of JPS and ratio requirements. This is especially true if we are just starting out at a place which has requirements. if I can't download anything to build a ratio with then I'm out of luck.
Sort torrents by filesize.
Download the 500 smallest torrents.
Seed them indefinitely for bonus points.
Spend bonus points on upload credit.