I'm a major "list" person. I have lists for everything - otherwise, I know my pigeon-holed brain would let things slip through the cracks. And to me, there's no better time for lists than when planning a vacation. I actually have an entire notebook dedicated to my travel lists - to-do's leading up to the getaway, packing lists, and then last-minute reminders.
You always want to ensure that you've ironed out any kinks before leaving on vacation - have you confirmed your flight and hotel (and car rental)? Have you cancelled mail and newspaper delivery (so as not to draw attention to your empty home)? Have you turned on your auto reply on your email at work?
It's also important to remember those random items that are so often forgotten when packing your suitcase and carry-on bag. My husband is notorious for forgetting basics, such as a belt, bathing suit, and dress socks (all items we've had to source at our destination upon arrival - no joke!). I'm more prone to forgetting the niceties - my cell phone charger (grrr- nothing is more aggravating!), a good book to read, or little things like earplugs (just in case). Write out lists based on your baggage (suitcase, carry-on, wallet) and try to start the list a few days before the trip so you can add things that you think of at the last minute.
And finally, don't forget a quick list of eleventh-hour to-do's. Is the timer for your living room lamp on? Is your outside porch light also on? Have you gassed up and done a quick car check (oil, tire pressure, and the like)?
Take it from this chronic list-maker - lists will ensure that all goes smoothly and nothing is looked over.