You could switch from cold to hot compresses as well as soaking your feet and ankles from cold to hot tubs of water.
Try wrapping them in ace bandages (not too tight - you don't want your toes to turn blue!), and elevate them above your heart. Especially at night when you go to bed.
Start wrapping at the ball of your foot and wrap upward over your foot, ankle and lower leg. You can also use those neoprene ankle supports available almost anywhere that has a pharmacy or sporting equipment. I use those often when traveling or hiking.
Check with your doctor to make sure the swelling isn't due to cardiovascular issues. If so, compression stockings might be needed.