Desert hiking shoes/ boots

What kind of shoes/ boots are good for walking in the sand dunes?
On previous trip, I found that my shoes immediately filled with sand and was wondering if anyone knows of a solution as I am planning another trip to the Kalahari.
Thanks for any response.

So far, I didn't find a way to avoid that... When climbing the sand dunes, it's best to just take your shoes off and walk on your socks, though! (No bare feet: the sand is too hot and the iron in the sand can give you some kind of skin irritation)