Quality

Layer Height: A smaller layer height is a fine print, but it takes longer! (I stick to the default options generally that are found in the dropdown right above this one labeled "Profiles")

Initial Layer Height: I've found no reason to mess with this, but it may help with adhesion for some people.

Line Width (and subsettings): Normally the width of your nozzle. (I've never found a reason to play with this either.)