@ligs welcome,
I, for example, seed 24/7
A good practice is just to leave your finished downloads to seed as much as possible.
Also, you can download and seed "Freeleech" torrents that have many leechers. This will not count against your download but will count against your upload
(Be aware of how many hours/minutes does a torrent have being freeleech)
All that being said, for some reason (I don't know why), there are (very long) periods of time where no matter how much I seed or how many leeches does a torrent have, I am unable to seed properly or at all
I am in such a period right now for about 3 weeks, maybe more