First of all, make an attractive video.. It should be interesting and fast, slow video can bore people. Add some creative messages to your video like credits, and tell them to like the video, by some interesting way like 'it will take only 0.1 sec to like it so just go like it and subscribe it'.
Secondly,give an interesting title to it. It should be creative, funny and describing ur video fluently. And a little description of ur video is very necessary. Most people forget this step but it is very useful to increase the viewers and appeal them to see the video.
Thirdly, after uploading ur video u have to work for its publicity like a movie. Share it on ur social networking sites like facebook,twitter,etc. Email it to ur friends, all the friends u know just email them and tell them to send it to their friends. Even i have lots of friends i will send it to my friend my email(email@example.com). I hope this will help u..