For DOM (as every INT flight for me starts as a DOM flight). I allow an hour minimum at the airport. So for a 7:00am flight, I will plan to be at the airport at 6:00am, which means leave home at 5:30am. If I am relying on someone else to take me to the airport I would allow an additional half an hour on top of that. So leave home at 5:00am. Yes I sometimes get teased by others about been super early, but I have yet to miss a flight.
I have cut it too fine once and it was not a pleasant feeling running through the airport praying that the plane didn't leave without me.
The way I figure it, I'd rather be relaxing in the lounge with coffee and pancakes or a beer / G&T, than sitting in traffic worried about making it on time, one way is super relaxing, the other way is stressful as nothing else.