Literally just post your work bro. You gain followers by (and this is the most important part) having a story to tell. Spamming slack jawed anime figures isn't going to get you followers unless you're really fucking good, but if you make images that evokes emotions such as laughter anger or sadness, you'll gain followers.
You can also gain followers by making porn, but unless you cater to unique fetishes or if you're (again) really fucking good, you won't gain followers.
Post a drawing you've made recently, it's most likely boring and is why you don't have followers.