Matching design sketches to the desired level of design feedback: "people reviewing a highly polished design may concentrate on superficial details and overlook fundamental issues. In the early stages of the process, you may be able to elicit deeper feedback by striving for an unfinished look in your design representations."

+1 - we (like many people) adopt deliberately "sketchy" styles for early-stage designs, precisely to avoid the "I like this, but can it be green" type of feedback you often get when showing off concepts.