Green tea
Drinking green tea enables your vessels to work better, including the ones in your feet.
Mix 1 spoon of green tea with hot water and keep it with a lid on for 5 minutes. Flavor with honey and drink 2 glasses of it every day.
Also, after keeping 3-4 bags of green tea in hot water for 10 minutes, you can keep your feet in this water for 10 minutes.