If you've ever been relaxing on the beach, admiring everyone else's sand castles, and wishing you knew how to build one - well, have we got a treat for you. Building a sand castle really isn't as difficult as it looks, and only requires a few key tools. So, grab your pail and shovel, and get digging. The most important step when building your castle is to make a strong foundation. After your foundation is done, build a pile of sand as big as your castle will be. After you have a good sized pile of sand, start carving and moving the sand to look like the castle you want. While working with the sand, keep it moist by spritzing it with a mister bottle. This keeps the sand sticky and makes it easier to work with.