Alright, so the first trick is to join a lot of relevant groups and submit your works to them; that will automatically give you more exposure, and more watchers.
Keep in mind that people tend to flock more towards fanart than they do original art. It really sucks, but that's how it is on this website. So like, if you made art of Billy & Mandy and submitted it to a Cartoon Network group, a lot of people would probably notice it and add it to their faves.
It also helps to watch other people and comment on their art. This helps with making friends on here.
Being a part of a fandom really, really helps, and regularly submitting works to groups that are a part of your fandom will get you a lot of attention.
These are just a few things to keep in mind. :>