As a frequent traveller, there are 7 rules that I live by when travelling by plane. For me these have become absolute laws of travel that make every trip easier and more enjoyable.
Plan what needs to be planned
Nothing is as stressful as realizing your forgot something so planing is very important. For each type of trip (business, conference, vacation, etc) I have pre-determined checklists to ensure I don't forget anything. If you don't have one ask a friend or email me.
Make sure your passport is up to date (having at least 6 months before expiry). Make sure you have all the required vaccines, visas, etc. Make at least 2 photocopies of each official document that you can keep just in case the original get's lost or stollen.
Plan your trip to the airport properly. I would rather get to the airport an hour earlier than required and comfortably check in, go through security and relax with a cold beverage at the gate rather than showing up late and constantly worrying about missing my flight.
Read my article about the importance of staying hydrated. The summary is avoid all caffeinated beverages and alcohol. Drink lots of water and drink it constantly.
Dehydration can make you sick and really contributes to jetlag.
I got to move it move it
Don't use your flight to be a couch potato. It is very important to move around and get some "exercise". by exercise I don't mean running, jumping or breaking a sweat but making sure you stretch your muscle and get the blood flowing. This makes you feel better, reduces jetlad and reduces the risk of deep vein thrombosis.
Get up and walk a little. Stretch your legs and calves. maybe even stretch you back, arms and shoulders. Walk, move, walk.
Airplane food is extra salty which dehydrates you. Don't use your trip to gorge. Eat normal portions and choose healthy options. Think veggies, fruits, etc.
Check with your doctor
If its been a while since your last physical, go to your doctor for a full physical and have a blood test done. This will ensure you are in tip top shape and won't have any surprises at your destination. Take extra meditations (if needed) and make sure you carry all your meds in the original pharmacy container which has the pharmacy name, medication name, dosage, your name and often the doctor's name. Some countries demand this or will confiscate your meds.
When I travel to some African countries, I bring along my own seringes just in case. For these I get a presciption from my doctor. I don't want anyone confusing me for a drug user.
Travel carry-on only
A huge frustration is waiting for your luggage at the destination or having it "delayed or lost". Read my article about travelling with a carry-on only.