I too had been warned against Miracle-Gro (too late since my first banana drowned in it). I currently use a mix that I believe was recommended to me on this forum: 1/3 potting soil, 1/3 perlite, and 1/3 peat moss. I've had nothing but great success and also use the same mix on all palms, bird of paradise, and other tropicals I'm growing. I'm using Scotts brand (all 3 parts) since it is readily available at Home Depot close to home.
Possibly next season I will mix up some of the organic ingredients that others are using to give the plants more nutrients, and do a side by side comparison with my current mix.