What are /r/SabuArt's favorite Products & Services?

From 3.5 billion Reddit comments

Tone value and color aren't easy tbh. It takes a lot of practice and observation.

https://www.amazon.com/Creative-Illustration-Andrew-Loomis/dp/1845769287

This book is really really helpful with the basics. I would look up a pdf or something if you don't want to buy it. Parts 2 and 3 are on tone and color.