First of all: those drawings look amazing, your style is certainly interesting. Take this critique with a mountain of salt because I am not as good as you.
Second: What are you trying to improve? Anatomy? Gesture? Expressions? Shading? Without a precise pointer is hard to give you tips.
Your chaotic lines are good for everything above the 30s. The 30s look too much chaotic, wobbly and amateur. I want to clarify, I am not critiquing your style, there is a difference between soft skills (free drawings, do what you want) and hard skills (perspective, technical drawings, gesture). When you hard ones reduce the stylish element, don't eliminate it completely, simply reduce it. If you want to know more about soft and hard skills I recommend you read The Little Book of Talent.
Third: I want to see your finished drawings. The red effect on paper is absolutely amazing.
Keep practising and improving and you will become great in no time.
PS: Which Brush makers did you use? I want to try them.