This is kind of silly... but isn't my worst idea. I've had a lot of fun playing it.
Play this on a 7' table. A lot of bars have those plastic electronic dart boards; borrow a dart and unscrew the fins... you're left with a pin you can stand upright. Place the pin in the middle of the table. Also borrow a cue ball from another table.
Now play cowboy, with the requirement of knocking over the pin after pocketing a ball. You must contact at least one rail before touching the pin. One point per success. Free practice if you're friends with the owner and nobody else wants to use the tables.
I guess the creativity comes out when you're trying to find ways to practice with limited time, lol!