Had to describe via text, but not much different than drawing a figure in the air, with just bare friction paying out line then clamping a bit to halt. A little flick creates the hitch, another settles it on the cleat.
80% of boat owners do it two handed and twist the hitch under; on a 30'er your fingers will just get sore if caught inside. A real vessel or something really pitching and/or rolling, you'll wind up with a nickname.