SWaPing - the key to structual integrity, longevity and ease of sculpting. SWaP is an acronym for Shovel, Water and Pack. Most pros recommend very wet sand, ie three parts water to one part sand. We'll start by watering down the base, digging the moat, and making large wet mounds where the walls, turrets and main towers of the castle will go. Molds - this is where the large bottomless containers come in.
Sand is Shovelled into the container, Watered and Packed by walking and stomping on it.
When it is as firm as possible, you add more sand, more water, and pack until the container is full and the sand is hard-packed. This process is repeated until a mound of the height desired is reached. The molds are then removed and the sculpting begins. Sculpting - this is always done from the top down on sand castles. Use your imagination, we have no pre- set design or plan.