Always bring along a light, stripped-down laptop or tablet that contains only the programs you need to do your work. Make certain you have charging cords as well. You can even store a small bag full of extra cords in your carry-on bag permanently. I keep a duplicate set of everything in my briefcase, so I don’t have to remember to unplug and pack anything.
You spend a fair amount of time in airports, so take advantage of any amenities they offer. If your favorite airline has a VIP lounge for frequent fliers, such as United’s United Club, a membership will cost you a few hundred dollars a year, but it's worth the cost if you travel a lot. In some cases, you can trade frequent flier miles for a VIP membership.
You'll have access to Wi-Fi, charging outlets, drinks and snacks, and perhaps most importantly, (relative) peace and quiet (even though they are crowded lately). Better the tappity-tap of fellow travelers' keyboards than the wailing of children or the background rumble of airplanes coming and going.
Whatever you do, spend some of your downtime charging your electronics, so you have the longest possible battery life while in the air. Running out of juice halfway through a five-hour flight may doom you to boredom for the rest of the trip, not to mention it’s counterproductive. Many large airliners have outlets, but they don't always charge your laptop properly. If there is Wi-Fi available, buy it. The $10 cost is worth the additional productivity boost from being able to send and receive email and access any webpages you need.
You can also use your frequent flier miles to upgrade from coach or business to first class. I bought up to first class recently for $99, so it’s often affordable. This will give you plenty of room to spread out.
If you're flying in crowded conditions in economy class, ask for an aisle seat so you'll have the elbow room you require. An iPad or similar high-power tablet may prove your salvation if you don’t get upgraded, so your poor screen won’t snap when the person in front of you puts the seat back.