I'm having a hard time expressing myself and that's part of the question - what words are used to describe spindle turning if any.
For example on a bowl we talk about foot size compared to the width of the bowl etc. There seems to be a ratio people at least start with. I'm wondering if there's anything similar with spindle work?
Here's a white oak pepper mill I just completed. It's ten inches tall. It looks rather boring to me.
View attachment 9833
I personally ignore all of those recommended ratios (some call "rules") and just make what looks right to me. When I started turning several people berated me for a foot too big, etc. My response (unspoken, of course): "That's what YOU think."
Mike Darlow has an excellent book "Woodturning Design" with a wealth of well-thought-out reasoning and illustration. He includes a lot of "classic" designs from history - the reason they are classic is because people liked them and duplicated them over and over! This book might be perfect for you.
With spindles, I tend to think of the size and shape of the parts relative to the whole. Think about how to combine the function with the balance. Again, a few sketches can help tremendously before putting chisel to wood - in the case of a pepper mill I would block out the size and position of the mechanism on a outline of the blank I had to work with, then sketch some possible shapes (with eraser in hand). I tend to design in my head while turning the wood round but that isn't always the best approach. Occasionally the color, variation, and figure of the wood will suggest something as I go.
There is nothing wrong with your pepper grinder shape but if you are not happy with it, you could try some different things. One thing might be to add some crisp detail at a place or two to give the eye more to look at, for example, instead of the rounded top of the base part and maybe at the bottom. Try changing the balance between the knob at the top and the base section. How would the knob on this one look a bit smaller? The function part: it can't be too small or you can't grip it easily. Ah, one small thing you might keep in mind when doing tall slender forms of any kind, be at least aware of any that might be, ah, "anatomically suggestive". There are a zillion variations possible - look at some pictures and find what you think is less boring and try to duplicate that!
One thing I've learned: No one shape is going to be pleasing to every person. The flip side: someone is going to love nearly any form you make!
I don't do many pepper mills, but this pair my wife tells me I made maybe 10 years ago, cocobolo for pepper and dogwood for salt (the dogwood is heavy wood so the weights of the two are very close):
We are happy with this shape. As for function, the knob feels good and is easy to turn and the upper part of the base defines a nice gripping place for the other hand. I've made a few others better and worse, to my eye.
JKJ