I'm working on a font in the same vein as Futura etc. I've used Miguel's spacing advice for the lowercase as I found it had the best results and forced me to evaluate properly rather than being too prescriptive (e.g. Walter Tracy's, which didn't seem to suit the profile and proportions of the lowercase). Miguel's system, along with my own judgement has worked well.

I'm now onto the uppercase. Starting with the H and O. My plan:

Using the categories in the back of Karen Cheng's book, I've divided up the UPPERCASE logically and am just using judgement and ideas behind the lowercase spacing, using H and O as a starting point.

Does anyone have any wisdom for this kind of sans serif – spacing and kerning?