>>1065965 (OP)
Create a main website. Write articles regularly and have a widget that will automatically share new posts to your social media pages without having to really manage them. Do promotion on social media but don't rely on an given site. Just use social media as a way to extend the reach of your content.
Put your videos on every video sharing site and put a link in the video description back to your actual website. Have lots of mirrors in case they get taken down. Try to automate your video posting process so after you make a video it will share to YouTube and mirror on other sites. Try to do this as much as possible.
Search engine optimization. Make sure you write good content. Best bet is to write human readable content instead of SEO copywriting and then rely on people to share your content on social media or blog and forum posts rather than. Spell check all of your articles. Make them MLA compliant etc. Validate your markup with W3C validator it's like spell check but for HTML.
Link build the fuck out of it.
Do a keyword and competition analysis with any free keyword suggestion tool. Best bet is get keywords that are easy but don't produce a lot of searches and as your link popularity goes up and you can start getting better keywords with higher search volume start copywriting and link building for those keywords. Put the keyword in your link's anchor text. This is primarily what tells people and search engines what your site is about.
Go to conferences where people who are in your field go and hand out business cards. Sometimes people will mention you on social media or in a blog post. Good way to get free ads. If you use a forum put a link to your main website or video channel in your forum signature. When you are making credible sounding posts in forums and whatnot people are likely to visit your site and if they like it share with others.
Blog rolls. If you already have a blog blog roll the link to your main site. This helps with search engine link popularity and keyword popularity as well.
Link begging. Make a post on your favorite board just saying something like Hey anons I've been posting on /tech/ for a while please share a link to the site with your friends.
Also another thought is do entry level, intermediate, and advanced concepts. This way you are reaching the broadest possible audience. If you go really niche with 1337 content you'll have a pretty small audience. If you go full on script kiddy, the more hardcore users will shy away. Have transitional content.
Couple of channels and YouTubers that are good examples. HAK5 and all of the spin off shows like Threatwire, Metasploit Minute, etc are good production value the people in the videos present the content well and topics covered appeal people of varying skills level, background, interest, etc.
Luke Smith's YouTube channel is 1337 content and complete autism and tech memes but because it's pretty niche there aren't a ton of subscribers. Good channel but not something mass marketable.
Thenewboston covers software development in multiple programming languages and beginner, intermediate, and some advanced topics like networking, crypto, game development, etc, with over 4300 videos and 2million + subscribers. And unlike most of the coding tutorials on YouTube now Bucky speaks English a first language so you understand what he is talking about. If you are learning a new programming language and you can't figure something out from the reference material just lookup whatever the topic is and you'll probably find one of Bucky's videos.