At home :
Make sure the battery is fresh
Make sure the spark plugs are fresh
Make sure the fittings are all greased , trailer too
Check the oil tank
Got drain plugs ? Got spare spark plugs ? Got minor tools ? 
Start the boat in the driveway .
On the way: Fresh gas at the pump.
At the marina:
Unleash the rear tiedowns.
Put in the drain plugs.
Pull out the dock rope so its easy to grab.
Start the boat again BEFORE heading to the ramp , a few seconds will do.
Back it down  3/4 of the way , pull the bow hook , drop it in.
It may seem like alot of steps, but once its routine , you dont even notice it , and the other nice folks at the ramp will appreciate it too. 
My kids have gotten pretty good at the " dog leash" dock style on the boat , even turning it around at the dock with a quick push and pull so Dad doesnt have to back it out. We are ALL learning.