Yes, believe it or not, some airlines actually let you check in 6 hours
before a flight.
What I do is, say, my flight leaves at 23:00, I arrive at 17:00, get checked-in, and go home. There I stay, watching TV
, on the computer, eating whatever I want to, reminding myself of anything I might've forgotten, resting, etcetera. Then, around 2 hours before the flight's scheduled departure time, or around 21:00 in this case, I drive over to the airport (fortunately it's only a quick 15 mile trip which takes about 20 minutes), get there at around 21:30 (after parking and everything), and only have 1.5 hours to wait. By the time I get through security, they're already boarding. So I just sit and wait for a little while, they call my rows, and I've had a great time waiting for my flight.
Yes, that's right, I arrive 6 hours
prior to scheduled departure time to check in for my flight.