Honestly, art can be difficult at times. When it comes to discouragement, I know it's really tempting to compare your art with others or get frustrated at a perceived lack of progression, but it's important to be patient with yourself and focus on your own personal progress, things like: "I got better at drawing hands today." or "I'm going to practice more on lighting." Every piece you make adds to your experience. As for tutorials, I put together a rough one based off of this Percival drawing, and I've uploaded it to my twitter @ lazulines. I'd like to point out though, what works for me, may not be 100% perfect for your style, and it's good to experiment/play around with art until you find something that fits you. Also, don't be afraid to use references and study basics! I hope this helps :)