For Team Up Requests -
Develop some pearl categories of your own and put enough pearls in your account to show you have a genuine interest in PearlTrees.
If you have well labeled, categorized and organized pearls of your own, it doesn't matter what they'e about, then ask if you're interested in joining one of my pearls.
I find it very hard to use pearls that have a large amount of individual bookmarks all over the place instead of using sub-categories to keep the numbers more manageable. I also find it hard to use individual pearls that don't have a label that tells what they're about. So I would like to see a potential team member who labels and organizes their pearls similar to the way I do with mine. Of course, if you have a better way of doing it than I do, I would be happy to adopt your way. :)