Not bad @Pounard, but you should leave no more than 2-3 pixels of empty space above the head and 2-3 pixels beneath the chin, and also include a collar.

Since in some sources, like the one from which this image was cut, the person in the image has a longer neck than usual or the collar is lower down, the above would be quite difficult to achieve naturally. Here's a technique of how this can be accomplished quite easily:

Have a look at this thread for guidelines for cutters and video tutorials on what we expect for from our cuts.

Much too small.