I can only speak for myself, as everybody will have their own routine, when it comes to going to the Atlanta airport.

I just retired after using the airport for 30 years. I know that airport pretty well, and I now how to make the trip to the airport very stress free, which is the name of the game.

There is on-site and off-site parking. In most cases, the off-site is cheaper, however you have to wait for the shuttle bus when you get back to Atlanta, which is not always super fast. That is why I always used on-site parking, so I could walk to my car, and not have to wait for a shuttle bus.

I mainly flew Delta, but I ALWAYS parked in the North (yes North), parking deck, so my car was under cover. Yes, I know Delta is on the south side of the airport, but parking in the North deck parking usually (not always), was less crowded, and a lot less of a hassle. (note...there is also on-site economy parking, which is cheaper than deck parking. Just an FYI).

As what time to get to the airport, I always tried to get there around 2 hours ahead of time. Yes, in most cases, I was early, but you absolutely never know how bad security will be. In matter of fact, one time when I was leaving on a Saturday morning, the security line was the worse I had ever seen it, and yes, that was in the summer. If you do get through security fast, look at the bright side. There is a lot less stress, and there are plenty of places in the airport to sit down and get breakfast.

Once you start using the Atlanta airport on a regular basis, you will develop your own routine, however, this is how I did it. Other people will have their routine, but this was mine, and it worked.

PS...one final thing, give yourself PLENTY of time to actually drive to the airport. You never know, (even on a Saturday morning), when there will be a problem on the interstates, that could slow you down. Again, an FYI.