Originally when I started thinking about scales, I had a vague idea to keep as close to a 1:10 ratio as possible. That is, each level being approximately 10 times larger or smaller than the previous. The advantage of this is easy multiplication in all cases. For example, you could take 10 hexes across and put them inside one single larger hex of the next scale up.
My musings on previous posts in the shower today made me reconsider that. A factor of 10 is convenient for some things (say, multiplying salaries: 1 GP for a "chunk," 10 GPs for a day, etc). However, its not so good for other things. For example, say you're mapping. I can't remember 10 hexes across. However, I might be able to remember 7. The 7+/-2 rule strikes again!
I'm not convinced that moving away from base 10 is worthwhile but its something worth thinking about.
OD&D Experience Levels
7 hours ago