A tourniquet for someone else isn't too hard to improvise if you've got the right belt or some strapping. For self-aid, though, you really want to have one that's purpose-built for one-handed application. The SWAT-T in the Patrol Officer's Pocket Trauma Kit doesn't fit that bill, I should really add a CAT-T to my laptop bag. Finding room for an IFAK in my laptop bag is excessive; I'm better off using that room for other things.

My most complete IFAK (http://www.narescue.com/USCG_IFAK-CN5B2F15EFB001.html, highly recommended, no affliation) is in my range bag. I've added a few things to it. It goes onto my belt when I'm on the range shooting or as an RSO. I keep a modified Army IFAK in my BOB.