Use store-bought driftwood for the structure of your orchid tree. Secure the end of the driftwood in a small Christmas tree base and put the "tree" in a spot with indirect light and good air circulation. Choose more specific sites based on individual orchid needs.
Decide on your orchid layout. Use miniature Phalaenopsis, Dendrobium, Oncidium and Vanda orchids for variety and color, but choose a range of orchids with similar growing needs. Hold the orchids to the wood to design your tree. Mark the wood with a pen or pencil to remember where the orchid root systems fall.
Soak peat moss in water and wrap it around the wood in your marked spots. Secure the peat moss with wire or twine to provide a growing base for the orchids.
Move orchids to the tree one at a time. Pull the orchids gently from their pots and brush away old potting material. Trim any dead or dried roots back to healthy root matter, then place the orchids against the wood, with roots against their designated peat moss bases.
Cover the orchid root systems with new sections of wet peat moss. Wrap wire or twine around the tree and peat moss sections to hold the "plantings."