Most sales coaches overwhelm trainees by pointing out too many problems at once. Pick one clear issue, give specific feedback on it, and follow up later. Multiple critiques at once actually makes people worse at selling.
Only give one piece of real, genuine feedback. The difficulty in being a good Coach is seeing 10 things that are wrong and only really going after one. And that's a difficult thing to do because a lot of people want to give you all the feedback because it makes them sound smart. If I want to make that person better, I need to be disciplined enough to tell them, work on this one thing, and I'll see you next week. And it's different for everybody. But most people cannot handle multiple pieces of feedback, and it puts them into a spiral, which is why when most people get sales training, they only get worse.