It’s always about thinking and planning ahead.
K.I.S.S: Keep It Simple, Stupid.
Be sure everyone on your team understands what’s expected. If a crew member is new, communicate with them what needs to be done.
Make signs to help alert strangers for where your filming. When every second counts, you can’t waste a take on a surprise walk on.
Be sure you don’t have issues with copyrighted images or product placement. Turn labels away from the camera, don’t wear shirts with logos. Simple enough.
Supplying meals? At least have beverages. Maybe some snacks if you wanna be a good person. If you aren’t feeling like being a good person, you could always tell your crew to bring a sack lunch. People probably won’t protest.
Be ready with crew, gear, cast and money.
Keeping on schedule. A script supervisor or unit production manager would be useful. It’s very easy to lose track of time. Don’t squander it, and have someone keep you on track.
Your most valuable treasure for an ONS is a fast editor. Be sure you leave them enough time. Always be thinking about how much time they will need. You could even hand footage to the editor during the shoot. Or have them work on the opening and closing credits when there isn’t anything else to cut.
Audio is crucial. Even in a timed competition, audio is key. People will forgive bad picture over bad audio. And having good audio in an ONS/48 is even more respectable, since it’s an often and tragically overlooked factor.
Find versatile actors. You never know where your story is going to go, so have actors that are willing to go out of their comfort zone. If they don’t know how to do that, they probably shouldn’t be an actor..but that’s just me.
As a director, be stern, but not too fierce. Don’t let the nerves and the pressure of timed competitions get to you and turn you into a monster.
These competitions are about building a skillset and supporting the community. Testing and challenging yourself. Things will not go perfectly. See how you react to setbacks and handle the difficulties.