I do SEO and thumbnails for a creator, and this week I went through their whole YouTube Studio. Same mistakes I keep seeing everywhere, so sharing in case it helps someone here. Mistake #1: Junk traffic that kills your channel One video had 85% of views coming from random sites and apps (external traffic), avg watch time 0:24. YouTube sees people leaving in seconds and stops recommending you. Check Analytics > Traffic source > External. If you see sites you don't recognise, stop whatever is sending them. Mistake #2: Sending your videos to friends and family Feels like support, but if your channel is for a US/UK audience and your family watches from another country, YouTube learns the wrong audience. One video even got a search term from a school student. Share only with people who would watch it anyway. Mistake #3: No chapters + numbers that don't match Two videos had zero chapters, and one title said $19K while the description said £19K. Small thing, but viewers notice and trust drops. Add chapters to every long video and keep numbers consistent. Mistake #4: Targeting keywords nobody searches The channel kept using a phrase in titles that barely shows up in YouTube search suggestions. Type your idea in the YouTube search bar first: if it doesn't autocomplete, almost nobody is searching it. The good news: the videos with fixed titles and thumbnails got 6–8% CTR vs 3.6% before. What's the one metric in your Studio that confuses you most? Happy to help in the comments.