There's an SVS course "Breathing Life into your Character Designs" but I also want to recommend the book Creating Stylized Characters, which has a lot of fundamentals for building a character, and even walks through the character design process from at least 4 artists. (The same company, 3DTotal, also makes the fantastic Character Design Quarterly magazine. The latest #6 is a treasure trove of talent and tips.)
Like you said, the answer for developing a character is also partially "draw this thing 1000 times." I am working on some characters for a personal project and the more I draw them, the more refined they become. One character is a horse and I actually found a large toy horse with articulated joints so I can pose it and see how it looks from different angles. This helps a ton!