I don't do a lot of potted plants but if you don't get answers here, post over in Container Gardening too or do some searching and reading over there. They have some favorite mixes.

Thank you for the suggestion, i posted the question over there.

I don't know.... Most homemade potting soil mixes are complicated and expensive enough to make you wish you went to the store and bought some. Priced a bag of perlite or vermiculite lately?

I mostly improvise. I had a real successful fig mix by mixing peat moss roughly 50-50 with fine screened (1/4 inch) compost. It's just exploding this year.

I've also riffed on the "gritty mix" formula by adding diatomaceous earth sweeping compound I got at the auto parts store. (Use respiratory protection!).

One thing about my homemade stuff is that it's a lot more durable than store bought potting mix. The stuff is usually better the second year than the first.

Don't mix it with garden soil but don't sweat it too much either.

I'm like you, though. Spending lots of money on bags of this and that is not where it's at. I try and keep my bag purchases to commodity type things.

I really should make some for the few summer porch pots we have. I recently made a pile of bark mulch by running sheets of bark (leftovers from my sawmill operation) through the chipper shredder. It made really nice stuff that I'm sure would be a good potting soil ingredient.