Shortly before closing, you'll want to call your service providers to cancel or transfer their services to your new residence, if applicable. It's wise to wait to coordinate with utility providers until the major contingencies are satisfied and you have a concrete close date that you can provide to the utility providers. This will avoid any wasted effort if the sale falls through.
Electric
Water
Gas
Trash
Cable, Satellite, and/or Internet
Homeowner's Insurance
Solar company
Home warranty
Landscapers
Pest or mosquito repellent companies
Cleaners
Here's a friendly reminder to complete some other tasks before or shortly after you move:
File a "Change of Address" form with the U.S. Post Office
Change the address on your driver's license