the wood
I work mainly in English hardwoods although some of my pieces are made from exotic timber. Where I chose to use non-native wood, I buy from suppliers who have reached or exceeded the minimum standards for importing sustainable timber.
Many times I've stumbled across an interesting piece of wood while out walking our dogs in Reigate. Some of these pieces end up as small pots and vases. Generally, they're branches trimmed by the local woodland manager, or trees which have fallen and broken.
My preference is to use native woods: it's immensely satisfying when people like a piece and I can tell them that the parent tree is still standing in a local parklands. Most of the pots will be made with a use in mind, even if they end up being used for something else.