If you're taking a plane ride, move your legs regularly and try to get up to use the bathroom or walk around the cabin if the flight crew allows it. And if you're taking a long car ride, stop regularly to stretch your legs and walk around. If you're a passenger in a long car ride, move your legs by raising your calf muscles up and down. 

Additionally, loosely fitting clothing is beneficial when it comes to circulation. The better the circulation, the less of a chance of developing DVT. Also avoid alcohol and caffeine, which contribute to dehydration. Increase your water intake. Dehydration causes the blood to thicken, which heightens the risk of developing DVT. 

Talk to your doctor about graduated compression stockings. They're often referred to as medical compression stockings. Like socks, they are worn daily. These stockings improve circulation. If your lifestyle is primarily sedentary, you run the risk of decreasing your circulation, which could increase the risk for clots.