look under my thread for "planting natalina", you'll see exactly how i plant my figs. basically, for each tree i'm using 15 gallons of potting soil. it's not your typical potting soil, it's a cheap bulk mix, and i am mixing a little sand with that as well. i try to plant 3 figs a week these days.
my problem out here is high ph. even my water's ph is too high. lots of natural lime here. so i try to mix a nice acid plant medium, and i give them frequent feedings of granular fertilizer. if i were living here, they'd be twice the size, since i could keep them sprayed with micros and use superthrive, etc. but this is the best i can do from long distance.
i'm hoping to get permanently moved out here next year, so i'll be able to really tend to my plants. i also have 20 varieties of muscadine grape, and i'm looking to expand my grape plantings.
i'll put up some pics when i get everything cleaned up out here. right now, i'm just trying to keep everything alive. i water it, i feed it, if it grows, it grows. so far i've been reasonably lucky.