I agree with Steve and Ron. Personally, I have mostly cork mounts, but do also have a variety of driftwood, tree fern, cedar and other mountings, including seashells. I use fishing line, but loosely tied to avoid strangling the roots.
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Hanging phals upside down or at a sideways angle is a good idea to avoid the rot. My first transplant phal was a Mini Mark Holmes, and now I have all my Potinaras and most of my mini-catts mounted this way. More time needed for more frequent watering, but if you have adequate moisture and humidity, excellent results!