Groups - Bump after 1-2 days for Advanced. As for Free/Casual, I don't know, if beyond the second page?
One on Ones - If it's on the first page, don't bump it. No one likes that guy. No one likes someone who bumps a thread that takes up space if it's not that old. We now have "Fresh" tags to help with that, so calm down guys. If it's on the second page but hasn't been a day, still don't bump it. If it's beyond the second page, go ahead. One on ones get bumps a lot, I'd rather people be sparing with them then not.