I think all you can really do is try to identify a common ancestor to those matches from their trees.
But in general, you need to analyze your matches, determining which groups of matches correspond to various sides of your family (in my experience, that means a particular great-grandparent or gt-gt grandparent) If a few of your matches match some members of a group, and don't match another group, then that's what part of your tree they're on.
The tricky thing is that even if you have a bunch of relatives with a given surname, that doesn't necessarily mean that it's a surname of an ancestor.
For closer relations, the centimorgans can help, as well at the centimorgans between known relatives and that same match.
Really, it just takes a lot of work, and perseverance, with no guarantee of success (like everything in genealogy!) That just makes it sweeter when you find something.
As far as "tricks", all I can think is maybe if you haven't noticed the feature for searching for a match with a given surname (or geographic place) in their tree. Sounds like maybe you've noticed "Shared Matches"., at least. The brand-new ThruLines might be helpful too (make sure you have your tree attached to your test results).