Bathrooms tend to be humid places anyway, but by keeping your plants in a tray full of wet gravel you will ensure a mini-environment for their special enjoyment. Most homes are too dry in winter, anyway, so if you want to go to the added trouble of getting a humidifier, your plants and sinuses will thank you many times over. Keep your Phalaenopsis orchids moist but not sopping wet. They have large attractive leaves, usually dark green with some purple tinges. If the leaves start to wrinkle your plants are way too dry.
Dendrobiums prefer to dry out between waterings.
Don t let them get so dry they go dormant and lose their leaves. If you mix up a weak solution, about strength, you can feed every time you water. Your plants will come home in full bloom. Phal flowers last for months. When the last bloom finally fades and falls off, DO NOT cut that long bloom spike.