If you're bored or unsure of what to draw, I could redirect you over to the https://www.newgrounds.com/bbs/topic/1491846/1 thread, where people post their OC's and you pick one to draw, you can also post your own OC's and people may draw them too.
I could also direct you over to the Looking for an Art Trade thread: https://www.newgrounds.com/bbs/topic/1545646 the OC one isn't always guaranteed you'll get something back, so here's a place to look for a mutual trade.
Other than that on the front page of NG there's a list of collaborations that you can either sign up or join in if you're looking for something to participate in.
TheAnythingGuy
Maybe try drawing something that's based on an art style we all know and love?