Just something quick - I wanted to share with you the brushes I use:
They are from a variety of sources, many of them have been around for ages from other artists (Jaime Jones, Kekai Kotaki,
Sometime ago, someone in my youtube channel told me he had just bought a brush pack, which really struck me the wrong way since I believe they should be shared freely with everyone. I really don't see the point in selling these as you can get them anywhere online these days if you research just a bit as fortunately there are still many people sharing them for free. It's also not like you are selling some secret painting sauce, it's just a simple tool. So yeah, don't buy brushes. And don't sell them either, don't be a douche!
Also, it's been said a million trillion times, but just keep in mind that they are just a tool and won't make you magically work better. They can be helpful if you are trying to achieve a certain look in your illustrations and so on, or to give some texture, but don't focus to much on gathering a ton of brushes and using them all. Just use the ones you are most comfortable with.
The last 10 brushes in that pack are probably the ones I use the most, but 80% of the time I use the same 2 or 3 brushes, the others are just flavor.
That's it! Let me know if you have any questions!