Useful advise when travelling to avoid DVT.
Exercise your calf and foot muscles regularly: Every half hour or so, bend and straighten your legs, feet and toes when you are seated. Press the balls of your feet down hard against the floor or foot rest every so often. This helps to increase the blood flow in your legs. Take a walk up and down the aisle every hour or so, when the seatbelt signs are not switched on. Make sure you have as much space as possible in front of you for your legs to move. So avoid having bags under the seat in front of you and recline your seat where possible. Take all opportunities to get up to stretch your legs, when there are stops in your journey. Drink normal amounts of fluid to avoid a lack of fluid in the body (dehydration).