Wet sand is the key to decent sandcastles. Once you understand this, building them is so much easier. The grimmest, dog muck covered beaches provide the material to build the palaces of your dreams. One with multiple tiers, and actual moats. Work hard enough, and you can dig out individual space. I managed a ballroom once.
When I visit the beach, I am an architect deep at work. I am building to beat the tide. But sand can only achieve so much.
The answer lay around me. Quite literally. There is nearby cove, where people often sunbathe alone.
You still have to be quick.
Everyone comments on how nice the colour of my creations are. The colour of the setting sun.
Wet sand is the key to decent sandcastles. Just do not assume this means seawater is involved.