Algorithm for calculating regular divisions of lengths in easy-to-read form
I would shoot for having about the same number of ticks each time, given that the tick values are acceptable. I am interpreting tick values as the constant difference between two tick values. Say you wanted to have about $n$ ticks and you are given a distance $d$. Then your tick values would be about $\frac{d}{n}$. Round this up or down to the nearest acceptable tick value.