How to keep shut-down Mac from starting up?
 

I understand the usual method of using the Energy Saver preferences to wake up the Mac up 1 minute before SD starts. But when I go on vacation, I want to shut down my Mac completely. If I forget to turn off the scheduled wake-up before shutting down my Mac, the Mac starts up at the set time, and I find it running happily when I come home. Is there any way around this? Is there any other option for waking a turned-on Mac other than the Energy Saver preferences?

Not that I'm aware of. Perhaps attach the Mac to a power strip and turn it off when you're going on vacation?