I clean my macbook screen with a eye glass cloth which usually cleans well. However for smudges I usually need to wet the cloth very lightly and then clean the screen. I read somewhere you shouldn't use normal water but I just use tap water because what else do I have? Sometimes this helps and othertimes it leaves worse smudges you need to use the cloth for quite a while to rub out.

What's the best way to clean the screen? Regardless my screen is always super clean but not sure if I've been doing it correctly.