I've started with a list of major markets I'd like to work in (or have ties to), medium markets I have ties to, and international cities I'd like to live for the summer. I have no idea how to compile firms, though. Are you just grabbing all firms from the area off of NALP?I think it was yellowbrickroad who recommended peppering all marginal markets that pay you the minimum you'd like to be paid. I might do this and figure that career services has a list of bull reasons we can give with no ties.
I'm debating whether to add Austin firms to the list and say that, although I've never been to Texas, it's been my dream to work in that great college town.
You might have a shot at Houston or possibly Dallas because there are so many more spots in those cities. I can guarantee with 99% certainty that you won't get a 1L or even a 2L summer job in Austin without some ties to Texas (preferrably Austin) unless you're at a T14, and even then your chances are extremely low unless you're at HYS. Austin is the most competitive market for SA spots in Texas, and they're really only interested in getting people that they are pretty sure are going to try and work here full time.