I observed two things about the rich ichi-no-ito tone that most pro players manage to get when watching a few videos today.
The first thing is about the normal way to play notes on ichi-no-ito with the ring finger. Now most of of us have heard that the thumb should remain stationary and it is just the ring finger that does the very slight slide to get that nice tone. Personally that has been hard but I just realized the way to make your brain get super tight muscle memory for the perfect pitch. If you watch a pro playing shamisen in slow motion (can be done on YouTube) you will see that the ring finger first does a slide, and then ends with the hand rotating a bit. It almost looks like person running and stopping suddenly and ends up standing straight (Hell of a comparison). At first I thought this was simply because the player’s hand was too small to comfortably move it all the way, but the good thing about doing this is that it is easier for you to stop in the right place and not slide too far. Try it out!
The second thing is that pro players bend the string a bit, and I believe this is one subtle key to a great sound because together with your slide it creates a wavy vibrato both horizontally and vertically. Compare that to a clinically clean slide without any bending. I’m sure you will prefer the bending way. I recently heard that Steve Vai (famous guitar player) is one player who utilizes this on guitar and I think that’s what made me think of this. Try it out!
And final reminder, don’t kill the vibration in the skin by holding the bachi on the skin after the snap unless you go for maebachi!