Here we go...
1- Add rich metadata related to your video (tags, description, titles,etc). Don't use random popular tags, youtube is not stupid.
2- Update your channel as frequently as possible. The more you upload, the more chances people will end up in one of your videos, and eventually people will subscribe to your channel.
3- Plan your stuff and do some research on your related videos, sort them by views, study them and come up with better ideas by modeling what successful people are doing.
4- Always watermark your videos with your logo or website's URL, you can do this with any video editing software.
5- Add the URL of your blog or website in the description areas of your videos and include a call to action such as "subscribe!" or "visit for more awesome videos".
6- Don't do sub4sub. It doesn't drive any traffic to your videos and you will look "cheap"
7- Try to become a youtube partner. If you own the content of your videos (you also need to own the music), you can share revenue with Youtube but most importantly, you'll be able to customize your youtube channel with your own header and cool graphics and people love that.
8- Create compelling and controversial content. If the content is not compelling, your video will not become to go viral.
9- Include the keyword "video" in your title and tags as many viewers' searches will likely include it, even if they search on google. If your video is a tutorial, add "how to", "guide" and "tutorial", if it is a review then
add "review", "compared" and "vs".
10- Keep your videos short. If your videos are too long, they may become boring after 5 minutes. If you make them very short, like 5 seconds and they are really good people will watch them at least one or two times more to check if they missed something.
11- Use Interesting and compelling thumbnails, more than 70% of views come from related videos so you want to make sure your thumbnails call viewers attention.
12- Allow people to rate, comment and embed your videos on their sites and blogs. (allowed by default)
13- Use annotations to display a call to action message like "subscribe to my videos" or to redirect your viewers to another video.
14- Only upload worth-watching videos.