There is literally no way good way. No tricks, nothing.
I got quite a lot of followers on my comics by doing nothing special. For instance: I don't have any following on social media, I don't update frequent, I never think about what my followers would like to see, I don't really interact with my followers nor with other people on Tapastic and I'm not active on the forums at all.
So I think not caring about your follower-count, but just making the comic you want to make, is the best way to get a followers. Because that's really the only thing I did.
BUT telling your friends and family to look at it may be rewarding, my mom was one of my first subscribers haha.