About spraying the leaves and watering in general. Water as early in the day as possible with and foliage moisture drying with in 4 hours. Use water with no chlorine ( fill a jug and let it sit in the air 24 hours to allow the chlorine to evaporate) You don't really need to spray the leaves unless it is for the purpose of watering or it is too hot and you need to cool the plants. If you need humidity and are windowsill growing, use pans under your plants. I use long narrow planter trays with inverted plant saucers for the orchids to sit on, and the water is in the trays. Do not let the plants sit in the water.