I looked back on my iPad to see what digital brushes I used the most in my illustration work, I have whittled it down to 10 that I use a lot, I think if I choose 10 and use these this will help my style to become more my own as it will keep the consistency and style the same, you will be able to recognise my work as my work without knowing the name attached to it.
I think my art and painting work is already very consistent, I have a painterly, detailed style with the watercolour work, but I need to show this through the digital work as well.
I found I used these 10 digital brushes the most :-
Watercolour
Studio pen
6B pencil
Chalk
Soft brush
Compressed
Clouds
Short hair
Flare
Flicks

I think these work well for my subject of illustration which is nature, and also gives a variety of brushes for any art work. I have bought a few digital brushes over the years, but I find that they are for a specific project or look, and the basic 10, core 10 that I would use on all art work would be these ones.