I'm a newbie, but my LT plan is to flat iron only 2-3x per year, especially until I hit my LT length goal. I don't blow dry at all now, but I may occasionally rock a blown out fro a few times a year in between PSs.
I plan to flat iron for the first time in December when I do my first real length check. I'm so nervous about it! I haven't had a setback yet, so I hope it doesn't lead to one.