First beach handstand and it's good to note that these are both harder and easier at the same time.
Factors to consider:
-Wind and it's direction, there was quite a bit pushing against my back body while inverted. This can certainly either help, hurt, or possibly not affect you at all.
-Type of sand: fine, hard-packed, soft, or pebbly. This is all about a hand feel thing for me, this sand was fine, soft, and a bit easier to sink into, which for me made it a bit better to hold the inversion once I found my center of balance.
In general when doing a handstand, I like to think of active, spider-like hands. Which if you've been a yoga student of mine, you're probably familiar with me saying "spider hands"! The first part to spider hands is spreading your fingers out instead of keeping them tightly together since you want to give yourself the widest possible base. The second part is to have the fingers slightly bent/curled to help you better grip, helping you grip better than if the fingers were flat and fully extended. Together, these two hand actions can help you have more control and stay up longer in the handstand position.