well, a few tips with thumbnails. 1. Make them appealing to the eyes. 2. Videos take time to grow. One thing you gotta have when making videos is patience. I, on occasion, take a day off from making videos just to let my videos grow in views. This helps keep your video count at a steady rate of uploading and gives your older videos a chance to be seen. Remember this: One video can make your channel a success but many videos on your channel could possibly be a waste of space