On my SP2 I added Restart and Power tiles (used OblyTile to do it) and just power down with one finger tap. I also changed what happens when you close lid under the power settings, set it to shutdown when the lid is closed (keyboard is closed).
I posted about this separately as well, but I'll add it here: it's possible that I accidentally hit the power switch when I put the SP3 in the case. I've noticed that the power button takes less than a second of depression to wake the SP3, and I've found myself accidentally hitting it and waking up the machine.
I don't know if anyone else agrees, but it seems like the power button responds too quickly (and/or is too easily depressed). Thoughts?