One thing I find really helpful for digital painting is to thoroughly get to know the brush engine. I did that when I starting using tablet. I looked at it section by section, slid all the sliders to the bottom, the middle and the top, one at a time, and see what happens. Tried all them little checkboxes and options. It's important to not only see how it looks, but understand what it's actually doing to your brush stroke. If you are friends with the brush engine, then you will know how to combine the settings for every occasion and task
Makes the painting process more enjoyable, and your artwork more personal.
By the looks of your picture, you have already got some knowledge of the brush engine, but you can't be too familiar with your software