Many organic materials, like peat moss, have a waxy outer coating that resists wetting. Be sure to apply water slowly to obtain uniform distribution. This may require 2-3 applications. It is not uncommon for a medium to look wet on the surface but to be powdery dry in the middle. A well moistened media will make it easier to stick cuttings later on.
Light is an important environmental factor in plant propagation.
Generally speaking, low light levels cause plants to root slowly. However, high light intensities can stress cuttings, causing them to burn or drop leaves. Diffused sunlight generally provides enough light for optimum rooting without causing injury to the cuttings. Since cuttings do not have roots, they cannot replace the water lost through transpiration. Therefore it is important to maintain high humidity around the cuttings to cut down on the amount of moisture lost to the atmosphere.