Well, after much trawling of tinternet, I've discovered that the Mikado likes to be humid and in a substrate medium - what the heck is that?! Not ordinary soil obviously.
As for the orchids, well I've discovered why I killed my last two off, over-watering and rotted the roots. As for soil, there are three types apparently but you're right Shirlton they do like to be a little cramped apparently. Ah well, we live and learn! ;D