Another method of growing your Instagram account is a little more experimental, but it's free. It's known as regramming.
Simply put, we're going to find people who post photos in our niche that get a lot of likes, share their photos (with permission) and hope they draw attention to our account because it shows how awesome they are.

We might reach out to a big account and say something like, "Hey, I love your photos. I'm trying to start a hashtag of surfing shots called #youcanthandthissurftho. Can I regram your pic to my account? I'll give your @ handle a shoutout." Almost everyone will say yes - you're offering to grow their exposure for free by tapping your audience. The interesting part is that many of these accounts will regram your photo.

What they don't realize is that in doing so they also allowed you to inject your account into their feed. I've seen regrams from one account alone pass over 15,000 followers.

It also carries with it the side benefit of getting closer to the influencers who drive a lot of traffic and conversions in a hashtag, but for our purposes this is secondary.