The best and simplest way is to keep it covered overnight. In addition, we recommend getting a high-quality stain for your wooden sandboxes in order to waterproof, so that it can last for years to come! For the sand itself, change it twice yearly! Get ultra-fine grain sand, and sift it after every use with a small metal rake. Finally, at the end of every play session check to make sure the sand quality hasn’t damaged any toy products in use….we all know how expensive those can be!