Oh wow, great portrait with some abstract colors! I hope it gets featured on the main page soon 
For some tips on painterly effects: I guess you can really like our newly introduced impasto effect, which allows to embed darker and lighter areas in a brushtip or use a texture as a map of lightness.
None of these have presets in default pack, so you may want to check out my brushpack or this short video on how to create this type of brushes:
For the other thing, you can pick a pattern and in its settings, set mode to “Lightness map”. I hope you’ll get some neat ideas on how to use those features in your workflow 