Maybe this is a silly question... I know to tip him/her 15%-20%, but I'm not sure when to physically hand over the cash. They're picking up my guests at 5pm, stopping at another hotel next to the venue and bringing everyone to the venue by 6. Then at 10:30 they're picking everyone up and taking them back to their hotels. Should I have someone hand him/her the tip as they arrive to the venue with my guests? Or wait until they pick everyone up at the end of the night? FH and I won't be taking the shuttle.
I want to make sure I do it at the right time because if they're expecting a tip early and don't get it, they may not be in a great mood for the ride home. I know I'm probably overthinking this, but when is the right time to do it?