A sample checklist or a project management of how to organize your preparation for a trip:

 

Early on, after initial deposit:
Get Travel Insurance
Arrange Airport transportation service
Verify Airline bookings on their website
Reorder medications and/or toiletries
Check Passport validity
Get the clothing you plan on taking to the dry cleaners

A week before departure
Notify Post Office of your travel dates
Copy/Scan all documents you are taking with you
Upload to a cloud service to have it available from everywhere. I use Evernote
If you travel with a tour company (group) check the FINAL DOCs provided
Investigate activities you are considering, like dancing etc.
Charge the Batteries of the gadgets you are taking
Notify friends and family about the specifics of your trip
Check and pay upcoming bills
Set TV recordings for shows you watch
Notify Banks of travel dates
Get some US cash in various bills for tips and cash purchases.
Prepare Document Folder for the physical documents
Prepare Social or Business cards
Download the Airline app
Download Google Translate languages
Transfer money to the bank account for ATM card use abroad
Prepare medication & toiletries for the duration

A day before departure:
Prepay Luggage if needed online, to save money.
Verify that your cash is ready
Check in online within 24 hours
Reconfirm Airport limo
In the Morning of departure:
Remove perishables from the fridge
Get garbage out from the house
Adjust Heating/Air-conditioning for your absence
Make sure everything else, specific to you situation at home is in order.