1.Keep expectations low. Comics seem to do better that Novels because they require less engagement to experience the story (aka less reading.) The more consistently you post the better you can do, but comics just grow faster.
2.Use the promotion threads, but don't spam. Promote in thread that you haven't already promoted in, and if its sub for sub, actually sub to some of the people in the thread. Don't expect everyone to just sub to yours.
3.Engage in the writing threads. A lot of writers here engage and talk with each other, and are often interested in reading each other's work, even if its not a promotion thread. DONT promote unless someone asks for your story tho.
4.Be consistent! If you post everyday, then make sure you post around the same time everyday. If you only update one a week, always update on that day! When people KNOW what day(s) to expect your updates they are more likely to stay engaged and sub that a story that randomly updates.
Hope these help!