Liner is the most demanding product in makeup for both steadiness and close vision, so this section is the important one.
Brace, do not steady. Elbow on the table, little finger on the cheekbone, pencil held close to the tip. Two points of contact plus a short lever removes most of the movement available to the tool. This is the whole technique and it is free.
Short marks, not strokes. Each mark is independent, so a shake affects only that mark rather than ruining a line. This is also why a pencil beats a liquid here — a liquid cannot be built from independent marks.
Use magnification to find the lash base. A standing lit mirror with a 10x panel makes the lash roots visible, which is what step four requires. Then check at 1x, because at 10x a line always looks thinner than it is.
Smudging is a feature. Step six means any mark that lands imperfectly gets absorbed into a shadow, so you are not aiming for a crisp line you have to achieve first time.
Consider skipping the pencil entirely. A matte shadow pressed along the lash base with a small brush or a fingertip gives definition with no line to keep straight — see easiest eyeliner to apply for seniors.
And a cotton bud with a little micellar water removes a mark instantly, so nothing about this has to be right on the first attempt.