Do not wakeup Mac on mouse movements

Go to System Preferences » Bluetooth » Advanced and turn off "Allow Bluetooth devices to wake this computer."

To wake the computer, you'll have to press the power button.

I do this because my iMac wakes itself up in the middle of the night.

Kind of a dumb answer but whenever you step away from the desk you can flip the mouse upside down.

I pull the mouse and keyboard usbs out slightly before the room gets cleaned, I just push them back in to turn it on.

For those of you without a bluetooth mouse you can put sticky tack over the laser and it won't wake up. Easy to remove and doesn't leave residue.

Most bluetooth mice of which I am familiar have a power switch on the bottom to save battery. If yours does, I suggest just turning off the mouse at night and back on the next day.