I've always made it a point to be prepared.  This also includes fire extinguishers and first aid/trauma kits.  In my truck, I carry a self made first aid/trauma kit.  Most first aid kits are loaded with bandaids, lotions and aspirin.  I wanted a kit that was better suited for job site or outdoor injuries.  Like injuries from livestock, chainsaws, job site tools, gunshot or knife injuries.  So, I put together a hybrid kit that has bleeding care supplies (clotting gauze etc.), tourniquet, sucking chest wound, splint, eyewash as well as a reasonable set of band aids. 
 I also made every member provide an emergency contact number.
What does everyone else do for first aid/trauma kits?