I saw a lot of people saying they post to social media, I do the same but that's just for friends and family who are interested in checking things out, not so much to grow. The thing I did that seemed to really help was Google Adwords, I stopped advertising my videos when I stopped creating vlogs, then started up gaming videos without adwords and saw the adverse effects. My audience reach was not nearly as far. If you want to grow I'd set up a cheap adwords, I think I did mine $1 a day or something like that and it promoted 30-40 clicks per day to my channel.
Don't get me wrong I love adwords, and the $1 a day wasn't even noticeable but something just didn't settle right with me paying for something so many grow naturally. So here I am, vlogger turned gamer just trying to grow my channel at the rate it used to haha.