When playing in a pool hall, don't try to be too fancy with a shot that you're unfamiliar with. You could easily end up tearing strips of felt from the table, or denting the slate top, which will ruin the table's balance. Either mistake can be a costly one.
Don't sit or lean on your favorite pool hall's tables. The rails in particular are delicate, and since the tolerances of a good table are measured in thousandths of an inch, it's easy to unbalance a table permanently if you rest too much weight on it.
