I like to use clubs to make community lots more fun to visit, so if there's a community lot you really enjoy, create a couple clubs that populate that lot designed to engage with one another. If you enjoy a particular bar for example, I would create a drinking club, pub games club, and maybe even a mixologists club, and set it up to have all three clubs interact with each other for some extra dimension or drama.
I also like to make custom NPC's using clubs by making a club populated by one or two sims. For example, before CoL I made a custom Misses Crumplebotton NPC by making a club with Mrs. C, that shows up at lounges, she knits, never flirts, is mean to everybody, and is constantly angry.
