Here's nice little example of some small Hugelbed 'Strawberry Tower' I made for a friend.
A large gnarly old stump w/ crazy
roots was placed at the center, many random logs/branches/leaves made up the rest of the bulk.
3 wooden frames were made of solid oak rough cut lumber.
Dimensions:
6 x 6 ft. (Base)
4 x 4 ft. (Mid)
2 x 2 ft. (Top)
each tier is about 10 inches high.
Soil was added one tier at a time, then the next wooden frame was added on top etc.
Potting Soil was used to top off each tier and transplanted with ever-bearing Strawberries she previously purchased.
Here's some progression photos: