A written remark expressing an opinion or reaction on songs uploaded via SoundCloud is the best way of getting more followers. Think of comments as a way to interact with other artists and possible fans. Find other DJs you like, start following them, and then add some comments to their tracks. The hope is that they will read your comments and then perhaps go to your profile and listen to your tracks, possibly even commenting back. Maybe they’ll follow you as well.
Also keep tabs on any new followers you get. In the top navigation bar, there is a Notifications tab. This will let you know of any new followers and users who have liked or commented on your track. Navigate to these users and follow them back; listen to some of their tracks and add some comments. At its most basic form, SoundCloud is a social networking tool, so don’t forget to use it as such. You want to network with other musicians and users in order to become popular and recognized by the music community.