You don't need to censor the art itself if you have it marked NSFW.
Also, I'd like to point out that NSFW doesn't vary depending on what you're "portraying" with your art. Nudity was and is not a sexuality thing unless it's used in an intentional sexual situation. NSFW has just one simple rule - would you show it to a child, your mother, or your boss? That is the only guideline you need - not what you're portraying, not what kind of "mood" you're going for, etc. If there's nudity, whether it's "casual" or not, it's best to mark it NSFW and be better safe than sorry.
If you mark it NSFW, you don't need to censor the artwork. I'm sorry if I sound angry, but I just don't understand why this is such a complicated subject for so many people xD""" It's simple and makes enough sense if you don't try and split so many hairs over it. It's not an opinionated or subjective matter. If it's got anything that would be listed on the back of an M-rated video game, or something that people wouldn't want to see without prior warning (dick pics eww), or -whatever- analogy you want to use, it's NSFW. Easy as that.
Drop a few F-bombs? NSFW (the F-bomb is considered a "level 3" swear word - basically any word you can't get away with saying on cable TV, unlike a few words that are allowed to slip under the radar because they actually mean something, like bitch or bastard; I heard the word bitch in Naruto the other day, it was really weird >.>)
Nudity, whether they're just undressing or just like to go free willie sometimes? Should be NSFW.
Lots of blood, gore, explicit and graphic violence? NSFW.
Sex scenes, whether light or super heavy? NSFW.
^^^^^ I seriously want this to get pinned so people can see what the actual guidelines are for NSFW and that it's not such a delicate issue because it's so easy to discern between what's okay and what's not. That's just how passionately angry I am about how much of a recurring subject this is for more reasons than it has to be :U