If it were me, I would start with

2 parts rocks/sand/dirt mix
1 part pea gravel
1 part compost

Mix it together and tweak the amounts of the ingrediants until you find the mix you want.

I'm trying the same sort of experiments right now with things I've collected throughout the winter. I've got some different things than you, but so far the mix above is most similiar to what has been working best for me.

I don't have any leaves, but if I did, I would put a thin layer on top of the containers for a mulch.

Looks like a good recipe, thanks. And, I may as well experiment a bit since I have enough containers to do that. I get good results with my own grass clippings for a mulch although I don't have much grass. I hesistate to use mulch from the community compost site cause I don't know what is in it. Also I am shredding Lil Caesars' pizza boxes for mulch this year since my son started working there and bring home some treats. Not the soiled part, just the covers. Another experiment.