Another little trick that I've been using for many years, ever since it occurred to me that this would be a sensible thing to do. I can't think why these things don't seem to be in 'how to knit' books, actually.
You know the problem - that very last stitch, right at the very end, always tends to stick out. Like this.
Just like the stair steps, really - except more so.
Sometimes we want a sharp corner, and sometimes it completely doesn't matter, so it is fine to leave it that way. But if you want to smooth it out - for instance, on a sleeve head, as here - then this is very easy to do. The method, as you've probably guessed already, is along the same lines with which we dealt with the stair steps.
So, when you come to knit that very last stitch in the final cast-off - don't work it. Instead, slip it purlwise.
Apologies for the blurry pictures - we all know that I am no photographer, but apparently I can even get 'point-and-shoot' wrong.
Now you've got just two stitches on your RH needle. Cast off the second stitch as usual, lifting it over the last stitch and off the end of the RH needle. Cut the yarn, leaving a good end as usual for weaving in, and take the end through that last stitch.
Much better, don't you think?