Solution of guitar left-handed fingering

The thumb just gently holds the back of the neck. Remember, try not to use your thumb hard.

Also in this picture, the whole hand shape is L-shaped instead of C-shaped, which shows that we rely not only on the strength of our fingers, but also on the strength of our whole hand.

So the direction of this force (yellow) of the whole hand is the same as the force (red) of our knuckles pressing the strings.

After talking about the whole hand, there are our fingers pressing the strings. We see in the above picture that vertical pressing is needed, which should be in line with the direction of the force we just drew.

If you press it on your stomach like the above picture, you will not only lose extra strength in vain, but also touch other strings by mistake.

Of course, it is also very important to look at this picture showing where our fingers touch the strings, and press with your fingertips, not your stomach!

The black shaded part in the figure is the correct touch position.