Here are some tips if you are more advanced in video optimization:

• YouTube is a video search engine but its primary benefit is that it’s a video sharing site. So optimizing is important but “video sharing strategy” is more important

• If you look at your metrics you will see that a HUGE proportion of your views come from Related Videos not from YouTube search results. In other words, people don’t just watch one video at a time, they watch videos and they are using the related videos