You need to set realistic time deadlines for moving tasks such as sorting and disposal, packing and cleaning to be done before move day. Then you need to strive to keep them. This way you will be fully prepared for your ultimate time deadline of move day as compared to going half insane with pressure if you procrastinate and wait until the last minute to try to get everything ready.
If people are going to help you sort, clean and pack then make a party day out of it, giving yourself plenty of hours to get everything done. A Saturday or Sunday usually works best because people are off from work and have spare time available. Have cleaning supplies and packing materials handy so that trips to the store are not necessary. This is a good time to use up your old cleaning supplies so that you won't have to move them on moving day. Have refreshments available for nibbling all thru the party but do not bring out alcoholic beverages until everything is done.
Confirm your moving date and time with all of your moving personnel well in advance. Plan to have an early breakfast at a nearby restaurant that you pay for on your day of move. Here, in a nice, friendly, casual environment you can relax, pull your thoughts together and advise each person of potential problems, elevator times, and special needs such as last minute packing, handyman work, etc before starting the moving task.
If possible plan for a second day to finish the move out of your old residence because you may need extra time to finish everything and to cleanup at either location. But if you must move in one day, when you confirm their planned participation request thar everyone plan to stay with you until the very end.
Try to get way more than enough people to commit to you to help you with your move. Make a hard job easy! On moving day things will get done very rapidly and easily if more than enough people are helping. One of the managers at Burrows Moving Company had to move his 5 room apartment from a high third floor to a his new residence on a second floor. He used 8 men instead of the usual 4 or 5 that most people would use on a move this size. The job was entirely finished in only 4 hours instead of 7 or 8 hours and then the movers were not all worn out. So, when they were done they all went out and got some beer and pizzas and spent the rest of the afternoon watching the football games!
And please be aware that some committed people will not make it on moving day for one reason or another, so by having more than enough people precommitted, you'll end up with at least just enough when this happens.