A lot of times, delays happen not because of problems getting out of the airport, but rather problems getting in. If you grab the first flight of the day, the plane will already be at the airport the night before, hours before your flight. E-tickets are becoming more popular, but they are not always best when faced with delays or cancellations. A paper ticket is a negotiable document and in most cases will be honored by other airlines. You can still get a paper ticket if you booked an e-ticket, but many times you will have to wait in lines, and that could cost you valuable time.
Alternate cities are also an option.
If you live in Chicago, try booking a flight out of Milwaukee. Or if you live in Denver, try Colorado Springs. In many cases, a short drive to a less-busier airport will actually save you money in the long run, and cut down on the hassles of delays. Finally, check on your aircraft number. Not the flight number, but the aircraft number.