1. Follow people that follow back. You can search for people using the following hash tags #follow4follow #followforfollower and #f4f .
2. Use hashtags that relate to your pictures so users can find find your account when searching for hashtags. You can download Likes With Tags to get Instagram tags.
3. You can exchange shoutouts with other Instagram users. You can check out Chamboost to find users to exchange shout outs with.
4. You can buy shoutouts from other Instagram users with more followers than you to help you grow.
5. If you are on other social networks such as Twitter, Facebook, you can make posts on there telling them abut your Instagram profile.
6. You can put your Instagram profile link in your email signature and / or signature on forums.
7. Like and comment on other peoples Instagram accounts so people will notice your account.
8. Post quality pictures that don’t suck. If you got nothing to post find quality stuff from other accounts and repost it. You can use Easy Repost to repost it.
9. Make posts that encourages users to tag their friends. Here is an example https://instagram.com/p/7-agknPHbn/?taken-by=thehustlerteam
10. Promote your Instagram account on physical objects such as a Business Card or T-shirts.
11. Have a contest that requires people to repost and tag their friends.
12. Connect your Instagram with your contact list so when your friends are searching for people to follow they will notice your account.
13. Do the same as mentioned above for Facebook. Connect your account with Facebook.
14. Make sure your account looks good. It’s like a landing page. Have a good bio and make sure the things you post are of quality. Which will result in higher follows when people end up on your Instagram page.
15. Post often but don’t post too frequently. If you literally post every single hour. You’ll end up having unfollowers and not many people would want to follow an account that spams their timeline.