I used: oil pastels, crayon, thin paint washes and smudge tools; on a green toned paper. This app has quite a few different coloured and textured surfaces to choose from. *I use my finger, rather than a stylus.
Like most artists, I find the best way to learn about the properties of different media, is to do lots of experimental sketches and drawings – whether it’s in an art app, on paper or on canvas. 🙂