Newbie mounting question

[Raqsharqi]

I had a phal that just wasn't making it, so I decided to mount it. Since phals supposedly grow with the leaves facing down, that's how I mounted it. It isn't doing anything much, but since it wasn't doing well to start with, the fact that it didn't up and die is encouraging.
I wonder, though, if there are any other orchids that like to have their leaves hanging down. I am getting some seedlings and want to try to mount them on Kool-logs, but didn't know if the normal procedure is to mount them all roots down, or if it varies by orchid type. How does one know what the orchid prefers?