The minimum stand height we have on the land I hunt is about 10' and the highest that we bow hunt from is around 26'. We build our stands in trees, and build ladder stands from treated lumber. Most of our stands are the ladder type, and we make them 16' high. That has proved high enough. However, I prefer getting up around 20' to help with scent dispersion if I can. The problem is finding the right tree in the right spot so that getting up to that height is safe enough.
When I was younger, I had stands that were no more than a seat nailed to a branch while I stood on other branches or crotches as high as 20' up. Now, I have much more of a fear of heights and falling as I get older. I like the fact the ladders are much safer and we've even been building frames with railings around them.