I agree, fur is tricky, especially because each fur is different (same with hair).
I go with the direction of the hair, working in layers, and mostly I pay attention to the structure and values.
The texture comes with mileage.
In addition, fur and hair are soft, so they do have softness to their edges.
You can use a synthetic brush (small one) to gently soften the fur or hair, but do not overdo it, so it won't look too smudgy.
In this article, I mostly showed sketches, which are much faster than drawings.
Meaning, you can draw fur and hair if you mostly focus on values, and transitions in values, with a bit of suggestion to the texture.
Sometimes, the texture is like small abstract triangles, if that makes sense.