It should be much like any other sort of marketing effort. Seek out some marketing books. Maybe pay a social media marketer to do some marketing for you if you

It should be much like any other sort of marketing effort. Seek out some marketing books. Maybe pay a social media marketer to do some marketing for you if you don't feel you have the necessary skills or can't pick them up fast enough. There's also good old fashioned networking, too. Find social coders with a similar style to you (and a reasonable audience) that you could be friends with / mesh well with. Try to make friends with them. Try to do streams after their regularly scheduled streams and encourage them to send their active audience along to your channel when they are done for the day. (That's what Twitch Raids are; Twitch built an entire viral networking tool for that.)