The most important piece of feedback startup people seem to struggle with is lack of clarity. Lack of clarity of vision, lack of clarity of who your customer is and their problem, lack of clarity in website copy. When something is unclear people will often reject it or try to impose their own view on it before understanding it. Instead I find it’s best to tell the person who lacks clarity what I find unclear and why and have them work to find clarity on their own if they know the product/customer/etc best.