What is the proper way to install blades of a receptacle up or down?

Up. ---- I'm not sure what the question is getting at. USUALLY THIS QUESTION IS ASKED WITH REGARD TO THE "GROUND" PRONG of a standard 3wire, 120 volt receptacle In the USA there are no requirements which dictate whether a receptacle outlet should be mounted with the ground UP or DOWN. In fact, it is also proper to mount the receptacle horizontally.