[chartrusepengui]

I suppose it depends on where you are and what you are comfortable with.
Some believe you need to be more formal to gain respect. We are comfortable being informal and have no problems with respect issues. We are friendly but not "friends". We introduce ourselves by first name to captains. We introduce ourselves to coaches by first and last names as we greet them, each time we greet them whether or not we already know each other.

This works for us - maybe not everyone. Do whatever you are comfortable with - or what your association has determined you should all use.