Ash paths-anyone any experience/tips on building?

here are instructions for a cinder path:-

http://www.plant-care.com/path-construction-and-maintenance.html

I once visited  a large home garden on a tour, and they'd laid a cinder path with cinders from the local rail yard that had a mountain they wanted rid of. It was certainly different, and one I wouldn't want to fall on or walk barefoot (as I often do) as the cinders were quite sharp. Youngsters would have a hard time walking on them. And you'd definitely need several layers of weed suppressant below. I find that the poly bags that animal feed comes in works well.

If you're thinking actual powdery ash from the woodburner, I wouldn't recommend it. If it doesn't blow away first, it'll stick to your shoes/boots every time it rains. And as said, its great stuff for the gardens.