There is no simple way except a good content to increase followers on Instagram in short time.
1. Focus on a good content.
2. Be consistent on your post.
3. Admire other user’s work. Like and comment on their post.
4. Post stories regular and show the best of your work.
5. Create polls and questions in your story.
6. Use hashtags in your post that more users will see your post.
7. Create an interesting and attractive bio.
8. Switch your personal account to business account.
9. Use location in your post.
10. Tag some big pages on your post that they can feature your post on their account.
11. Use locations and hashtags in your stories too to get feature.
Write a good caption.
12. Post videos also. Videos get more attention than the pictures.
13. Share your account on other social media accounts.
14. Promote your post on Instagram. Use Instagram ad service.
15. Make a good engagement with users with using live video session.
16. Post pictures and videos on a good time when users are using Instagram more.
17. Follow those users who are doing the same work. Take inspiration from them.
18. Avoid taking followers from third party apps.