Here are a few ideas:
1. Will he mention that he blocked flights from China?
2. Over/Under on how many questions he will take.
3. Over/Under on how many people he will place blame on.
4. Will he tell any journalists... "QUIET!"?
5. When asked a question he doesn't like... will he say "Are you ready? Are you ready?"
6. Over/Under on how many journalists he will cut off before they finish asking their question.
7. How many times will he say words like "Greatest, Powerful, Best, Incredible, etc etc"?
8. Over/Under on how long the briefings will last.
9. Over/Under on how long into the briefing before Trump mentions he blocked flights from China.
These are just a few ideas... I'm sure others could think of many more.
Btw, if anyone EVER wants to bet me on whether or not Trump will mention that he blocked flights from China on any given day I will take any and all action. I'm not sure how many of these briefings we've had so far but he's mentioned it in every single one of them and I expect this to continue for the next several months.