I keep a doc with things to discuss. The doc is accessible on phone & computer. So, whenever something important pops up, I add it to the doc. Here are the things I do as an employee.
1 - Follow up on previous 1on1 if required.
2 - Discuss concerns/problems & solutions.
3 - Advertise my achievements at high level.
4 - Appreciate specific teammates for any significant help.
I exchange brief pleasantries, but I like to keep chit chat at a minimum in these sessions so that we can focus on important things & not get distracted. There is always time for chit chat outside of the 1on1. Sometimes, when there is nothing to discuss, I ask if its ok to meet anyway just to do chit chat & catch up. This can be helpful depending on how well you know your manager, & especially in remote work these days.