I winterize, but every year i worry that i have forgot to do something. Never had a problem - yet.
I try turning off the water at the source, open all faucets, disconnect anything that may cause a problem. Unplug everything. Put water heater on 'vacation'. Put anti freeze in washing machine. Most of our neighbors know we are gone and keep an eye open for us. Forward mail to our son, who can open anything he thinks is important. Pre-paid all bills I can. Cancel Time Warner. Paid anthing i can via internet. Power bill is drafted.
But I still think about 'what did i forget'.