I part my hair in small sections & add the powder then blend it with my fingers. Since my hair is Jet Black,I have to make sure it's completely blended,or it'll leave my roots looking Grey. I also add the powder after I style it.
Not at all. I usually just grab some of my hair from the top and flip it over, shake a little bit of the Osis powder on, put my hair back over it and work it in with my fingers. If you don't have enough volume, backcomb it a little bit.