I've found that going midweek can cheapen the tickets, and that the longer you wait (closer to time you want to leave), the more expensive they get. Unless you want to gamble a bit and go for last minute deals when they're trying to unload any extras, which I guess would be okay if you don't have a set date that you want to leave. I find it cheaper to leave from a smaller airport (Toledo, Ohio) than it is to leave from larger airports not too far away (like Detroit or Columbus)...I don't know why that has been. I think Detroit is sometimes cheapest for my area, but with the cost of gas to get there, or a cab ride, it wouldn't be worth the saved $40 or so anyway. So if you need to factor in gas money, remember to take that into account! I'm also one to spend a bit more to get a better itinerary...I'd rather pay a bit more than have 12 hour layovers every again
This is random, but what are you taking for money? Traveller's checks, cash, and/or credit/debit? I took travel checks once and they were a hassle...HSBC didn't believe that AAA was a legit travel company and took over 45 minutes to cash my checks after they checked around. Maybe it was just them though, I don't know
Though some consider it risky to take a lot of cash, I like to take it because you can exchange it for free at the post office