Select a place and time to OBSERVE
If there is a particular subculture you are able to identify include this as well.
Spend a few minutes acclimating yourself to the site.
Who is there what activity is occurring how many people are involved.
Then spend five minutes writing down everything that you observe.
Be as specific and detailed as you possibly can no detail is too small or insignificant. Keep track of a few individuals if you can not keep track of everyone.
Each movement should be explained almost as if you are writing for someone who has never seen any of this behavior before.