Practicing at the beach is very challenging. The constant movement of the sand underneath you makes it difficult to stay grounded. When I'm practicing at the beach, I have to ground myself mentally first. If your mind can't be steady and calm, then you'll be like a rolling wave before it crashes.
Next I focus on my breathing. Calm breathing translates to a calm mind and body. Steady breathing keeps your body steady and still. I think of myself as a boulder in the ocean. The boulder stays grounded. It confines itself in their own space. Unwavered by the chaotic crashing waves which resembles the mind.
The beach has many things to teach us. Step outside and see what lessons you will learn.