Generally I'm working overtime making sure I've got everything squared away or properly on pause/reassigned to someone before I leave. It's always worth that extra legwork to make sure I can spend my vacation completely disconnected and relaxed, not giving a second of thought to work.
The 2-3 days before a big vacation, we are usually occupied by logistics - getting the dogs set up with whomever they'll be staying with, eating all the food in the fridge, paying up all our bills that will come due, etc.
And usually Mrs. Lee finds a need to do some last minute clothes shopping.