After flying twice all by myself with our two little girls, I have collected a list of things that worked for me and helped me keep my sanity. My girls are currently 16 months and a little over three years old. A few month plus or minus can obviously make a big difference, so this list might not work for everyone. But it did for me.
If you have an older toddler, like I do, preparation helps a lot. We started talking about the flight very early on. I explained Sophie what would happen and why daddy would bring us to the airport but could not join the flight. We got a book about the airport from my mom and read it several times ahead of time and even on the plane and at the airport. This helped her a lot, I think, and got her excited about the flight. I also explained a lot to her during take-off and landing and we gave her the window seat so that she could watch the trees, cars, houses etc.
Children feed off your mood. Meaning if you are stressed and anxious they are more likely to be stressed out too. I was trying to relax as much as possible about the flight. Always remember: Nothing can really happen. You are trapped on a plane, they cannot escape. Yes, they will scream at some point but really, who cares? If people make stupid comments or roll their eyes at you, simply remind them that infants can't talk, so screaming is their way of talking to you. On our flight from Honolulu to Portland a mom and her screaming infant were seated a few rows ahead of us. A guy sitting right in front of us could not stop making silly faces, stupid comments, etc. I told him that I did not think he was funny. He apologized and stopped. Sometimes it's enough to call people out.
On the first flight with both of them I brought way too many books and toys. We did not use them at all. Focus on key toys like a lovie and maybe a favorite book. Even better: a new book or a new toy that keeps them occupied. For younger toddlers - don't bring toys at all. Ella only played with a cup and straw and an empty water bottle (she stuffed everything in the motion sickness bag and took it out again and again and again). The other toys and books were not interesting enough to her. She loved watching other passengers too and walked around of course. Which brings me to the next point.
4. The iPad
If you are flying with two, there will be several occasions where you'll need your older one to just sit on her seat while you carry the younger one around, change diapers, etc. The iPad was a life saver for me. I downloaded some of Sophie's favorite shows and some games (this was her absolute favorite!) and she was entertained for a while. Now I know that some of you will not like the thought of keeping your child busy with an iPad and I agree that screen time should be limited at this age, but think of it this way: YOU are the one who chose to go on this flight, a 3-year old has a hard time sitting still for so long so I think YOU also need to find a way to keep them happy and entertained.
5. The Ergo
If your younger child is not an infant anymore, they might have a hard time falling asleep on the plane. Lots of unfamiliar noises, people, stimulation. At least my kids are this way. I know that and brought my Ergo. When I noticed that Ella got tired, I simply put her in the Ergo, stood up and walked a bit (with the sun cover on so that she wouldn't be distracted) and waited until she was asleep. I was then able to sit down with her strapped to me and she napped up to an hour this way. This way she never got so overtired that she would start screaming her head off.
While most European airlines still serve food (the quality is another topic), almost all US airlines don't. So food is important. I suggest not only packing food like a lunch/dinner but also packing your children's favorite snacks plus some things that they usually want but don't get on a regular basis. The best snacks are the one's that keep them occupied for a while, say lollipops or in our case fruit strips. They take a while to be eaten and my kids love them.
7. Clothes, clothes and more clothes.
Sophie is potty trained but the thought of her sitting on an airplane for five hours without a diaper made me nervous. She surprised me - she had no accidents and even used the toilet on the plane. Big girl! Ella on the otherhand kept wetting herself despite wearing a diaper. Why you ask? I have no idea. Maybe she was drinking too much at a time, wiggling around too much.. I don't know. I only know that we had to change her completely up to three times on a 5-hour flight. So extra clothes were necessary.
8. A blanket or two.
I took two old Aden and Anais baby blankets on the plane with me, since it tends to get cold. You can use them for soo many things. As a blanket to keep your little one's warm, you can build a tent with them over the airplane seat and hide underneath, you can play peek-a-boo, etc. We got a lot of use out of them.
9. Successful packing
I had two carry one items (not including Sophie's backpack which contained her books and some toys). One bag was filled with stuff that I would need immediately - food, diapers, changing pad, wipes, water bottles, iPad, you name it. The other bag was packed with all the extras - change of clothes, extra diapers, blankets,... stuff that I would need at some point but not immediately. This bag was placed in the overhead bin while the other one was under the front seat, so that I could reach it easily. This type of packing helped me a lot.
10. Chat up your neighbor and ask for help if you need it!
Somehow I always got lucky with my immediate seat neighbors, they were super nice and of great help. I suggest to always greet your neighbor friendly and say something like: "I want to apologize for my kids ahead of time, they are usually very happy but might scream at some point on this flight. I hope we won't bother you." Something to break the ice. And then try to chat them up a bit, ask where they are going, etc. They are more likely to help you out if you talked to them about other things before and it helps pass the time as well. I love to hear about other people's lives.
Of course, there will always be something you did not prepare for. But that is life. Be positive and always remember: the flight is only xy hours long. Your life will hopefully last waaaaaaaaay longer, so try to relax and make the best out of it.