Oil Pastels?
There is something exciting about using oil pastels. Firstly you can work quickly which I love. The colours are added in layers. I have to add white to areas I want to keep light. When you build up the layers of colour, you can scape off any excess and start over!
There is an unavoidable stage where the picture looks like a 5-year old has been let loose with your pastels. Just stick with it, you will work through this stage quickly enough and watch your art develop in front of your eyes.
Scrape off pastel where it is too thick.
Sgraffito
This is a technique where you scape and scratch off the surface excess oil pastel to reveal with colours underneath.