I have a [www.hobbyking.com] watt meter in the 12V line. This way, I can see what voltage I´ve set on the PSU ( 12V regular, but 14V to heat up quicker )
Also at the end of a printjob, I can see the consumed Wh.
-Olaf
if you want to measure everything, best way to measure the line coming in. One of the best consumer devices to do this: Kill-A-Watt. [www.p3international.com]