I mist lightly between waterings and they are ok. I grow mine cold in winter and warm in summer.........they are ok but could be better. I should water the coccinea hybrids a lot more than I do when it's cooler. But I think intermittent mistings is a great solution.
For what it's worth, I recently had issue with low humidity as well. I grow in my house, and couldn't keep the humidity up to 40% even with ultrasonic cool mist humidifiers. So, I bought an evaporative whole house humidifier, and wa la! My humidity levels are staying at 50% or higher, which is great. IT's a Vonair, and it works wonderfully. Amazon!
I have about ten feet of orchids in a south window, all on top of humidity trays. The room is open to other rooms. The humidity was about 30%. I started running a warm air humidifier. I cannot contain the humidity to the room since it was open. This one humidifier, running full tilt, got the humidity near the plants up into the 40's. I added a second humidifier. This let me get the humidity to 60%. Could probably go a little higher running both at full blast. I usual keep it in the range of 45-55% near the orchids, and the air in the entire first floor of our house is also benefitting. We noticed that we feel a lot better ourselves having more humidity in the air.