OK, so far I've figured out the best way to watch videos without ads for free:

You can watch YouTube videos for free on the Bing website (the videos might be blurrier though). 

Posting and sharing a YouTube video to tumblr, instagram, Facebook and Twitter are the best ways to see a video for free without ads. 

If you post a link to a YouTube video on Dreamwidth, the link takes you to YouTube - which still has ads unless you pay about Fifteen Australian Dollars a month to have the ads removed. 

You can enlarge a YouTube video by left clicking your mouse arrow/cursor the square shaped button in the lower right hand side of the video. 

Click on the round button on the bottom of the video to fast forward or reverse/go back to a previous part of a YouTube video. :)