You are already on the typical therapy to reduce the ulcers. Hydroxyurea and keeping the Hb higher are the main treatments. Wearing compression bandages or socks and elevation of the feet for a couple hours per day (during sleeping is the best way to find a couple hours) can also help. Vasodilators that help open the blood vessels, such as L-carnitine may also have some value, and since L-carnitine is one of the supplements routinely advised for thals, it's a smart move to take it daily.