More from the redoubtable VanderMeer and Booklife on The Discovery Process: Improving Your Abilities. I don’t think any writer should ever get to the point where they think they know everything about writing – or that they don’t need an editor. You should be honest about your abilities and know what your strengths and weaknesses are … and if you can recognise your weaknesses, then here’s a thought: try to fix or at least improve them.
http://booklifenow.com/2009/10/the-discovery-process-improving-your-abilities/