I do my best to avoid flights that are very early in the morning, and avoid flights that will require me to drive to the airport in rush hour.
The packing part is the most stressful. If I get everything packed the day before I do much better, including any paperwork needed, identification, directions, maps, and money. Usually my bag for toiletries still needs to be finished after I get ready that morning, but even that I leave everything I want to take with me out the night before on my vanity. I check the weather where I am going. I have some usual travel duds I almost always bring with me, so some of it is systematic. I used to agonize getting everything into a carry-on, especially in winter months (winter clothes take up a lot of space) but now with the liquids restrictions I often have to check, so I went ahead and bought a bigger suitcase and now I never have trouble with space for all the clothes I want to bring. When in doubt I go ahead and pack it. Packing was much easier in the days when I wore black all the time. Fewer shoes to think about. I still tend to bring mostly black, and items that go with black or denim.
If you have a lot of anxiety about getting to the airport, but also hate the idea of spending over two hours waiting at the airport, consider eating a meal at the airport before your flight. A nice leisurely lunch easily takes an hour, and most major airports have some very nice restaurant areas. In FL all the airports I have been to have free wifi, and I can easily kill an hour on fluther. When I am in MI I have a few stores I like to shop in at the airport. I have quite a few t-shirts and sweatshirts from one of the stores in Detroit airprot. Some airports even have places to get manicures, take a nap, messages, all sorts of stuff now.
I get alerts from Delta if a flight is delayed. Probably most airlines have that. It just happened to me in NYC, my flight was delayed about 40 minutes. The result was it wound up I could slow down in my last minutes of getting my act together.