Well-said, Yuri.

Wow, thanks, Mikhail! A *very complete tutorial, including your texture and map optimizations!
You are contributing to my Blender education as well as for #B4W.
Please do more tuts –as time permits!

Surely "tuts" are other-than any developer's favorite page to produce– and tutorials take considerable effort and time to do well.
A few notes:
•The animated .gifs are great to view changes in sequence and directly compare steps. Maybe a blank 0.2sec frame inserted at the end would tell the viewer that "the loop is beginning again?" Just a thought.
• Possibly add a link to a sequential frames page? That would aid my viewing on mobiles, which is where I often read new info.
• a circle-over (or arrow toward) each teaching point may help new users learn the blender UI as well.
• Your beautiful model seems high in polys– is further economy possible? Only if your procedural masks are omitted?
I learned a lot from your work. THANKS!