I just happen to have been reading RHS about orchids this afternoon. As they like humidity (and they are not all the same so worth further research) stand on a 1 centimetre deep gravel bed which is kept moist. This is not the same thing as leaving the whole pot standing in water. It is quite easy to over feed orchids so a feed once a month is sufficient, I am told. Also they are mostly forest plants so enjoy shade and, lastly, they often need a bit of drying out or a bit of cooler temperature to stimulate flowering.