How much should I seed?

I've found that if I seed to the full potential that my download speeds are better. If I limit my upload speed for any particular torrent then my download speed suffers.

You have to remember that on a private tracker, having a ratio of 3, 4 or 5 can be a bit selfish. If you have a high upload speed, and you quickly upload a lot, it could mean that people with lower upload speeds can't upload enough and get banned, even though they want to upload more.

Personally, I think, be sensible about it, and have a ratio between 1 and 2. Seed torrents that there aren't many seeds on, not ones that have loads of seeds, that way the rare ones are kept alive longer. Just use your common sense.

I just make sure I keep it above 1.

I don't really worry about individual files. I just make sure that my overall ratio, on each tracker, is above 1.

That seems fair.

I would seed at 150%

On a public tracker its not as important, but on a private tracker you should definatly seed as much as you can

turn it to full speed when you are not using pc, I found it's not easy to seed on site like TB, S/L is always like 130/8, but that's why the speed is always good there.