Rule 101, take your shot, then set up.
You may not get another opportunity so it’s always best to work quickly in the beginning. When we first arrived at this spot it was more about finding a (safe) gap in the tall grasses.
There was also a flock of White Pelicans nearby, but out of range. If either group was spooked they all leave, quickly.
Luck was with us. They were hungry and all looked to be young. Juveniles follow the older birds when they take off.