Gather materials such as
branches, wood… for the bottom. This creates a breeding ground for beneficial insects who will speed up decomposition.
twigs, brambles, sticks… to create volume and anchor all the thinner material.
leaves, paper,cardboard, grass, weeds, nettles, hay, and anything similar… piled on top.
And finally mud or soil to cover the top. If there is not much available just use a handful were you have planted seeds or seedlings.
Try to get the bed at least one foot off the floor
That’s it. This can be used just about anywhere, especially carparks! In gardens, mulch the bottom of the Hugel bed to stop weeds coming through.
Using the same idea, get an oil barrel, make holes at the bottom and fill it up with anything you find around. A good dose of urine occasionally, will keep the levels of nutrients up. As time goes by the material inside the barrel will shrink, especially in the first few weeks. Brambles will hopefully hold the structure together in time for the roots of the plant to anchor.