Your feet bear the load weight of the body. For people with swollen feet at day's end, walking and moving the feet and ankles up and down can help as it circulates blood back to the heart. The swelling that results causes pain, exacerbated by shoes that might not accommodate it. Elevating your feet or rubbing them can help.
Stretching exercises can help also. A stretch that can help relieve pain is to stand with arms out in front and pressing against a wall or other surface, bend at the waist and extend one foot behind the other until you feel the stretch in your calf. Your heels should be flat on the ground.

Soaking your feet in Epsom salt foot baths are considered soothing, and can relieve muscle soreness. Some people attribute Epsom salt's therapeutic effect to magnesium sulfate, which may draw out excess fluid in the feet, as well.
Weight loss can also help since your feet and ankles support your entire body weight, even a small amount of weight loss can take an exponential amount of weight off the foot. Every pound of weight lost is like 3 to 4 pounds in decreased pressure on the feet and ankles.
If the pain persists after a full night's rest, continues or gets worse, stops you from getting through the day or doing something you enjoy, have a doctor take a look at it. It could be a sign of tendon problems, arthritis in the foot or ankle, or a stress fracture.