Be helpful in the right places. You really have to be devoted to working and being helpful though. For example, the easiest badge to grab is probably the Pre-Contributor badge, which you can get for generally helpfulness (examples include Sixonesix and mattj) or by writing analyses while doing peer edits in C&C (Snorlaxe, Komodo, etc).
Yeah, my partner started the thread so it looks like I don't have a trade thread. =P