Yup, I watched it yesterday. Very professional (yeah, I know you hate that word =)
This should be number one tutorial for beginner tile artists, it covers many important points.
I liked that you didn't just go and draw those tiles, but also very well explained WHY it should be drawn like that. Many facts are useful not only for tiles, but for sprites too.
In short... good job =) Are you already thinking about making another one?
BTW, I'm guessing English is not your first language?