Holy hell cop out answers just flow around here. lol. Facebook is useless without a huge friends list. Twitter equally useless. Forums bring in very limited views because forum members often subscribe too easily and too quickly to channels resulting in mass culling of subscriptions later and never actually watching content.
Now, here's some real suggestions.
Forum use can be beneficial but you need to make yourself very active and an expert of something. It doesn't matter what you're an expert at, but you need some reason for other forum members to drop your name. Then of course you need some form of link in your signature. I'm an audiophile and know a lot about sound, so I posted a great amount of stuff in the editing forum about mics, etc. I also have an audio tutorial in my signature which has 1310 views, 88 likes, 2 dislikes and 57 comments. Which are stellar ratios and most of the traffic to that video is from this site.
Reddit is an excellent resource but you need to have a thick skin. You also need to research and make sure you're putting your post in the right place and not only spamming your own videos. Post other things too. If you do get hate, it generally won't pass on to your video comments or dislikes. And if you get too much hate early, the post will simply not gain any momentum. If the post gets to the point where it generates a lot of hate, it also MUST by Reddit mechanics have received more upvotes than down.
And last but not least, be an honest critic of your own work. Look at it and ask yourself if one of your friends posted it, would you click like or share? For the vast majority of channels and content on YouTube, the answer to that question is no.