Since I had always trouble in drawing convincing noses I made some considerations about the main volumes of the nose-tip.
In general, the lower region of the nose is formed by a main spherical shape and two adjacent small spheres. After some cutting and addition of the lower curves, the nose-tip looks convincing. Furthermore, thinking in volumes makes is much easier to crate the later shading for the nose.
The detailed steps are shown in the picture below.
Have fun drawing noses 🙂