I do use photoshop to draw! As for the brushes I used... Do you know Shiyoon Kim? He's a fantastic character designer working for disney, and his sketchy ink style is kind of his trademark. You can get his brushes here: gumroad.com/l/shiyoonink They're not for free, but they're definitely great! Your decision if they're worth the 10$. If you don't want to spend any money I recommend Ramonn60's brushpack, which is pay-what-you-want: gumroad.com/ramonn90 The one at the top is the brush I'm talking about. I drew this picture with that brush: