As one of my students was setting up her tripod in an open, yet tight, spot, a photographer walked in front of our student and said, rather curtly, "That's my spot."
My student responded, "It's an open spot No one is here."
The very rude student from the other workshop said, "I was here first, I'm setting up my second tripod." (It was a tripod with a second camera and a $3,000+ lens.)
I was shocked. I said to my student, "Hang in."
I walked around for about two minutes and found a clear spot for my student. She got wonderful images - as did all of our workshop students.
As usual, after all our students were set up with "first class" spots, I set up my tripod in "coach," behind the students, and in some cases next to the students where there was room.
On a side note, I often take pictures on site and show the students the shot to illustrate a composition or lighting technique. After all, one reason photographers come on my workshops is to see how I shoot.