Personally I use 20-20-20 at 1/2 tsp per gallon.
I used to use 30-10-10 when I was growing in a fir bark mixture. The theory was back then that the higher nitrogen number 30 was important because as the beasties broke the bark media down they would rob the plant of nitrogen at the same time. Recent research seems to have debunked that!
The idea of a " Blossum Booster" like 10-30-20 every third feeding would increase flower count and frequency. That has been debunked as well. Hence I use 20-20-20.
NEVER leave standing water anywhere near the roots. Orchid growing experts also have debunked the notion of misting plants to increase humidity. Why? Because if your house has low humidity, say 35%, you can't mist enough to significantly change that locally for your orchids! The water vapor you think you are adding to improve humidity instantly gets absorbed by the drier room and house. The water vapor does not hang or hover around the orchids for any length of time.
