The difference between losing the net and owning it in beach tennis often comes down to one thing: whether you've read the wind before the match starts. Wind off the water behaves differently than inland wind — it tends to shift in gusts rather than blowing steady.
When you arrive at the court, watch the flags or loose sand for two minutes. Note the direction and decide which end you'd prefer to serve from if you win the toss. Into-wind serves sit up higher and are easier for opponents to attack; with-wind serves kick faster but are harder to place.
During the match, watch the ball's flight on your opponent's toss before returns. A ball that drifts left on the toss means you should cheat right on your split step. Adjust once, adjust early, and stop adjusting — chasing the wind mid-rally is how you give up the net.