Found a cheap fight? Great! Keep the trip cheap with these advices of frugality:
Bring a pic-nick. Bring your sandwich, apple, snack or similar in you carry on bag. Do not plan to eat on plane or airport but always bring a snack anyway. Delays do happen and food is also comfort.
Bring an empty water bottle from home. It has to be empty when going through the security. After that it can be filled up in any water tap with cold water. The same goes for a Thermos of coffee but it can be more difficult to fill without paying for it.
If you didn’t bring a bottle from home – find one at the airport, rinse and fill in bathroom. They are easiest found right before security (make sure it is empty) or around the waste bins next to the water bottle machines. Are you grossed out reusing a water bottle somebody else has drunk out of? Remember that there is a price to pay for being sensitive (the grossed-ness cost). Never forget to bring your own bottle again and this time go without. However, consider the contamination risk seriously – be rational about it.
Pack hand luggage only. With a frugal wardrobe you will not have much to bring anyway.
Do not pack a pocketknife! Make sure all your fluid bottles are either empty or a size 100 ml or less (NB: not the content, it is the size of the bottle that counts.)
Pack headphones with a regular plug. Modern trains and planes sometimes offer radio/film entertainment and sell headphones for it. But the plug is (usually) a standard size so bring from home. Alternatively bring the headphones for your electronic device if you have one but then you also have to bring the charger and you will be restricted in your mobility.
Travel inexpensively to the airport. Check in advance and plan to take the cheapest available option when travelling to the airport. Usually there is a local bus somewhere close by. As you will have only hand luggage, those extra couple of hundred meters will not hurt you.
Find reading material at the airport. Left newspapers can often be found everywhere. International travels are interesting, but the language is almost irrelevant if it is only to be used to pass time. Most hotels, especially the cheap ones, have an exchange bookshelf bulging with books. You do not have to bring any. (Expensive hotels usually do not have this; can anybody explain this to me?) Also read all reading material, including advertisement during the flight. Ask to share the neighbours paper. You do not need to buy reading material. There are also always thinking to be done.
Do not stress. Stress clouds your judgement. Check in time is the earliest you need to be at the gate – not the latest. If you have a seat reservation and there are no special instructions for security (depending on where you are going to/from) you can plan to have gone through security at the time of the gate opening. How long time security takes is sadly impossible to know.
If you have plenty of time at an airport: Exercise. Walk the entire area and all terminals and to all gates. It is free exercise, you open for opportunities to meet people and find great newspapers. Being a bit tired also helps sleeping on the plane.