As I fly from airport to airport the only way I can be 100% I will be departing again is to leave one engine spinning.  I usually leave #3 going and the APU because its the first in the start procedure.  Doing this I havent had the other engines not start.  I have had to abort flights in the past because I have shut all the engines down and been unable to get them restarted........Not sure why, I have a 68 step laminated start checklist that I use everytime to ensure I am doing the same thing everytime.  Sometimes it works, sometimes it doesnt.  Kind of frusterating.

What do you use to turn off an engine?  Fuel shut off?  Prop control?