I create a master spreadsheet and pack over the course of a few weeks.
I try to put things mostly in boxes that correspond to rooms but get overwhelmed halfway through and honestly end up just doing whatever I can to get from one house to the other.
I hire some movers.
I trust that it will all get done on time, but I try to work on it bit by bit. Mostly I just focus on not stressing myself out.
I procrastinate a whole lot, but when I get into gear I get it all done in a night.