I'll admit that I don't really do much for my Instagram. I have a weird following on there that doesn't pertain to my YT channel because of my personal posts xD
However, I have been trying to build an audience on Twitter. I try to respond to all of my follower's replies or @'s. If I get a new follower (that isn't a bot), I interact with them by going through their twitter to see if I like anything (and heart it) and I reply to some that I enjoy I have a small base on Twitter, so it's a bit easier to go through and keep myself updated with the active followers. From time to time, I'll have polls for fun or for the next video idea.
I do a bit of Twitter, Pinterest and LinkedIn, but those aren't really where much of my audience comes from. My audience is older. They spend most of their time of old-school forums much like this. That's really where I focus. I use the other social media platforms just for the links to help the video rank better within YouTube-Google ecosystem.
Really I just use those other platform to help drive traffic to the YouTube videos.
For me on other social's it's about finding hashtags relevant to the content I am creating, so that it can lead to discovery on those platforms naturally. I also focus on diversifying it, and making sure that if people follow me, they know what to expect, but still keeps to what I promised!
I don’t “build an audience” for the sake of building an audience, I interact on social media for the genuine community and sharing thoughts. On Instagram I just want people to see my art, and if they like it and follow, that’s a bonus.
I’ve heard some influencers say to comment more on other people’s content, and not just “good”. Give valued thoughts and people will organically follow. That’s how I’ve been growing my twitter following. It always surprised me when someone follows me on Instagram because I don’t think what I do is all that interesting. Half the time on twitter I’m just trying not to go on rage arguments against people who are closed minded and bigoted haha.
So hashtags are good, but Gary vee and some others have put a lot of emphasis in getting into the comments, share your thoughts on other people’s content, and they’ll naturally find you interesting enough to come to you.