(I know everyone has their own tips, but these are mine and these work for us)
1. Bring books.
Jack loves his books. The skinny paperback books are really easy to squeeze in your already packed bag, but they will be worth it. Buy a few new ones before the trip so they are new to your child. Jack tends to pay more attention to new things than stuff he's played with or read before.
2. Bring an extra bottle, snacks, diaper, wipes, & outfit.
I know this sounds crazy since your bag is full, but if you have to land somewhere that's not home or your destination and you don't have a diaper or a bottle... you'll regret it. It's happened to me. I had a cute new diaper bag that didn't hold much and I thought, with my flight being so short, I could do with packing light. Oh no. Big mistake. Bad idea. I got stuck in Houston for 3-4 hours with a screaming, hungry, dirty little boy. It was the hardest trip. So bring a couple extras. It's worth it.
3. Speaking of snacks....
Bring non-messy snacks. Jack is a too old for baby food, but the "smoothie-in-a-bag" things work so well on planes. They are only messy if they are squeezed really hard.
4. If you have an iPhone or iPad, take advantage of it!
I know a lot of people dislike TV and/or letting their kid's mushy brain watch it, but when you're on a flight with a grouchy lady to one side and a sleeping man on the other, you'll want your child to hush for as long as you can make it happen. Load it up with new shows or movies. Or, if you have an account, take advantage of Netflix. There are a few good (educational) shows on there.
5. Bring a comfort item.
If you kid sleeps with a blanket all the time or a teddy or anything that makes them comfortable, then bring it. It'll help keep them calm.
6. Stay calm.
I've had to tell myself this so many times. Jack has had a few meltdowns while waiting to load the plane. Since I look so young, people tend to judge me, especially when Jack is melting down. I have to repeat "calm down," "relax," "don't worry about them, worry about Jack," & "it'll be over soon."
Flying with a toddler or baby is hard. Especially if you are alone. Stay calm and bring the essentials and you'll be fine.
I've already started packing Jack's bag ( I always throw in my stuff at the end). Here's what I've included so far... and some that I'll be including later..