Should I Leave My Printer On or Off?

no prob with both 

The difference between leaving your printer on or turning it off is generally insignificant in terms of energy costs. For healthier print heads and more efficient ink consumption, however, it's better to leave your printer on

You can turn it on when use and turn it off when off.

I think you turn  it off

turn it off when not using it.

In an office environment, the first to arrive turns it on and the last to leave turns it off. At home, you turn it on only if you are going to use it. 

If your printer has bluetooth capability, turn it on only when you are about to pair with it. Otherwise, some nut nearby can print on it and you'll hear him swearing for the pages not reaching him although he has spent your whole paper tray already!

yes                     

Unless you use it daily there is no good reason to leave it on. Most newer printers but off after a certain amount of time of non-use. 

I don't think it makes a lot of difference, most printers will shut themselves down after a certain time.  I leave my printer on, because the surge of power to the printer circuits are more harsh on the electronics than leaving it on.