One of the cons of being self-taught is that it's all trial and error. It's easy to miss and struggle with some very obvious things. I do wish I'd had the opportunity to learn from a professional illustrator. It's difficult to get certain processes and techniques into your own head without someone repeatedly impressing those upon you.
For instance: It's utterly imperative that, when creating a character, you decide on a real person to base the character on. It's also imperative to sketch that person from at least a few angles. There are nuances - facial and body structures, expressions and postures, that simply cannot be pulled solely from your imagination. After a lot of experience, maybe it's possible to pull solely from your imagination, but, even so, it's still best to pull from reality. This is all so obvious, but, being self-taught, it's a step that I've given little attention to. And, HONESTLY, it's not mentioned in any of the books that I have! And I have quite a few! The best resource I've found on this is on Scott McDaniel's website - he has a ton of free and useful information for aspiring artists.
A few years ago, I took time off of work and was determined to finish a six page Spider-Man submission. I spent literally months trying to come up with Peter Parker - entirely from my head, because a) I was LAZY, b) I couldn't settle on an actor to reference, and c) I was concerned that using reference would make my work look boring and static. The result was that ALL of my faces not only didn't look like Peter Parker, but they looked awkward and alien.
So, if you're an idiot like me, get rid of your ego and get some damned reference - especially for character faces! Don't hide behind your artistic influences - especially anime/manga! And don't worry about losing your 'style' by learning from reference. It can only enhance your work if you use it correctly.