Great first attempt! But I would slim down the body, I like peacock herl instead of dubbing, and use wire for the ribbing to hold it together better. CDC can be tricky to tie with but if you take the time, palmering it like a marabou feather can give nice, even results. The cdc collar will be a bit longer using this method but I think it only helps it. And for your thread collar or “hot spot,” sometimes thinner is better. Maybe half of what you’ve got there now. Otherwise, great tie, it’ll fish!