Some soil I made up today:
50% screened pumice (<1/4 inch)
25% cocofiber
25% compost
Depending on how much of a hurry I'm in and the number of holes at the bottom of the pot, I might lay down a monolayer (ie. a layer one rock thick) of chunky pumice (>1/4 inch size) before starting with the soil. This seems to help with some plants after years of settling and further composting has taken place, to ensure the bottom of the pot still drains freely. Time does have effects on the density and openness of soil mixes when there is organic matter involved.
