Hi!
Just watched your video, and since you want to learn, I´d be happy to comment your seat. Seat is kind of my speciality...
In general, you seem to be doing fine! I´m sure you could just keep on, and you´d get better! Great work!
But my job is to be a bit more specific, so here we go;
- The most important part of your seat is your pelvis. It looks like yours is in a relatively good position.
BUT, and this is important; You sit a bit too far back in the saddle. I believe this is due to tight muscles around the hip joint. It might also be the denims
The way to correct this, is by relaxing your legs as much as you can while riding. If you manage to relax, and still get that sensation of weary muscles after the session, you probably did it right... The idea is to make the weight of your legs stretch the muscles while trotting. Some seated trotting sithout stirrups, perhaps?
Next, you slouch a little. This is a bit of a danger to correct, since I do not want you to become swaybacked! This is important! You should raise your chest a bit, trying to balance your head on top of your now- straight spine, but be certain to hold some tension in your abs. finding your correct balance is hard work, but it´ll be easy when you get there.
The balanced seat you get, will help you keep your hands still!
Good work so far, and good luck!
Pelle