I have a lot of time to observe as a dolly grip. Here are some things I see:
Setting a flag isn't a two man job. Just back away once he has it in the c-stand. You aren't helping. Let it go.
Everything isn't a question. Don't ask me if I'm coming off the track or where the next track is going. I don't know yet.
Be a grip, not a gopher. Learn how to light. Observe the set. Look for things that stick out. Keep looking. You'll always find something.
If you are low on something, go get more of it. I don't care how close the truck is, make a decent staging area and keep it replenished.
It's a craft, just like bricklaying or plumbing. Learn your craft. Don't just be a gopher.
Be proactive. Are there lights bleeding onto the bluescreen? Fix it. It's your job. Try to anticipate what is needed before it's called for.
Thus endeth the lesson.