Fertilization
This part is easy, but is often done very wrong. Keep it simple and you will have great success.
Fertilizer
Use organic soil conditioner. Avoid the big name commercial fertilizers, they can be too much for your delicate indoor plants. A simple rule of thumb is if the fertilizer smells like poo, it’s the one for you.
Schedule
Fertilize your plants during the growing season (spring and summer) about once a month.
There is no need to fertilize during the winter as plants don’t do much growing when it’s cold and the sun isn’t as strong.