Righty tighty, lefty loosey updated
If you ever need to remember which way to turn a nut, bolt or screw to loosen it, then the mnemonic above will help. Turn it to the left (also known as anti-clockwise).
But one more thing to remember:
you need to have the eye looking at the nut, the bolt head or the screw head, with the thing it’s attached to beyond it. This pretty much is the usual way of looking at the piece of work. One exception is a limescale filter attached to a water tap (common in Spain). To get the eye in the right position for this mnemonic you would have to put your head right into the wash basin, twist your neck and look up at the filter on the tap. It’s easier to just look down on the tap and reverse the rule – clockwise as seen from above loosens it.
All the above only applies to fittings with right-handed screw threads. The vast majority. There are a few exceptions of left-handed screw threads, such as left bicycle pedals and gas pipes as detailed here.