Many people get very confused on what they should do or shouldn't do when it comes to the airport. Here are the few things that I do to save time for domestic and international flights. The key is preparation.
1. Download airline app on your phone and check into your flight using the app this way you can add your boarding pass to your "wallet" app if you have an iPhone.
2. Checking bags: I have been able to travel with just carry on bags for all of my trips. I save money and time this way not having to get in line when I get to the airport and have to go to baggage claim when I land.
3. TSA Precheck: I finally bought this last year. It is $85 and lasts for 5 years!!!! It is as lifesaver! Now remember, this is only for when in airports in the US. You will not have this luxury in other countries.
4. Mobile Passport: This is a free app you can download. When you land back in the US, you would input your info and it will give you a barcode to show customs. There is a special line near global entry for this so you can skip the regular customs line YAYYYY!!!!! (global entry is the same thing minus mobile passport is free and you don't have to go through a whole interview process) I got through US Customs in 2 minutes!!!! Highly recommend.