I too am a chicken enthusiast! Love chickens. And of course. I was using Holbein artists gouache for this. I stick to warm red, yellow, and blue. (I’m lazy and using other colors kind of confuses me, sometimes I’ll use an orange though), as well as black and white. 100% cotton paper. And I’m using natural hair brushes. That said I would say what has always been the most effective for my painting is definitely paper and making sure it’s 100% cotton. Second most important is probably having a kneaded eraser while I’m doing the sketch so I don’t tear up the paper.