"When you’re just starting out on Instagram, growth will feel painfully slow. Those first couple hundred followers may take you a while, but once you establish a routine and get some momentum going it will pick up, so stick with it!"
Take a look at this handy blog post on the CD Baby site with great techniques to get more followers on Instagram.
http://diymusician.cdbaby.com/social-media/how-to-get-more-followers-on-instagram/