On long flights, I wear 2 pairs of compression socks- one knee high and one ankle. I always get an aisle seat and also do ankle pumps often (20 reps each, evey half hour or so). During layovers, I walk and walk and walk- alot of airports have art installations now and great views from different areas. If it's a long wait, I like to walk over to the international gates- fun to people watch/see the uniforms of international carrier staff.