In prenatal yoga we lay on our back with butt and legs against the wall, like your legs are straight up against it. 10 min or so, it seems to help.
If you are on your feet quite a bit I would get TED hose/ support stockings. They really do a good job at keeping the swelling down. Helps with blood flow and can decrease getting varicose veins. Also prop your feet above your heart.
Ya and try not to be eating a lot of foods with a lot of salt
Drink lots of water and keep them elevated above the rest of your legs