We also book as soon as it goes at or below the rate I'm comfortable with. For my September trips...the highest I will pay is $200/RT/direct. So when it falls below that, I book. Incidently, I booked my Sept airfare last Friday since it was $199 (figured I wasn't getting much better than that with gas going up) and the price jumped $103 more on Sat!
Personally I start watching my flights everyday after I decide when I am going or at least once a week. I set a certain price I want to pay such as from STL to MCO I really don't want to pay over 100.00 each way per ticket. I watch about 2 or 3 airlines including SWA which doesn't even open their flights until a few months ahead of time. But if I find one that is below my set amount and no stop overs and for the times I want I usually jump on it. I was right the last trip we took when we got AA for 79.00 each way because they never did go lower even with SWA Ding.
Just a last week AA again had our flight we wanted for 79.00 and I had a coupon from the Entertainment Book for 5% off making it 75.05 each way so we again booked it even though SWA has not opened up yet. Since they are talking about gas going up I didn't want to wait and take a chance. (the price usually is 148.00 each way so I am happy but I will still keep watching)
Can you fly SouthWest and use the Magical Express?