[wayner]

When I did mine I cribbed from inside and used hrydolic jacks on those cribs to lift and then block it so that I could work on sections using a small backhoe from the outside.

I built a 8 foot tall, 6" thick wooden foundation (following code using preserved plywood and for extra peace of mind, a barrier layer before backfilling with sand and drainage pipe).

At the base I poured footings to build the wall on. I also insulated the cavity of the 6" thick wall using blue styrofoam.

If your digging a trench, be careful about working in it.