How specific should I go with tags? I mean how to tag states tag what I see but is there like a reccomended minimum I should tag? And is there such thing as overtagging?

Basically you should tag amount of people - *boy and *girl tags, additionally solo or solo_focus is necessary. Then hair and eye color, hair length for females, hair ornaments, clothing items and accessories - possibly as many as you can. Then scenery - indoors or outdoors, then specify if possible, like classroom for indoors or forest for outdoors. Also tag water if any, like river or lake, plants like tree or flower - specify these if possible too. If there if no scenery, tag the background - white, black, transparent, simple. Then posture - standing, sitting or lying, more specifically - arm or leg movements and gestures. You may also tag emotions or expressionless, looking tags like looking_at_viewer, looking_afar, etc.
Also, if you tagged something and the tag has only one post, don't just leave it, try using other words for the item, maybe you're just denoting it wrong. Also use the tag search on top of the page, or create a thread and ask a question.
If you get about 20 tags for an image like this post #24476, it's okay.

Aslo for identifiable characters tag alternate, adapted and embellished costume, cosplay, costume switch, alternate_hairstyle, dual or multiple persona, known relationships like mother_and_son, sisters or family in general, and crossover if necessary. Don't forget spoilers!
Oh, and also tag specific furniture.
Try reading the tag wikis for everything I listed, you may find more tags and useful links there.
I'll add things if I remember anything else.

In short: Tag whatever things you can find in a single picture/what you see, is what you tag.

howto:tag mentions what the bare minimum for tagging is. Though you should always try to tag as much as you can past the minimum.

Tonny890 said:

And is there such thing as overtagging?

No.

Gotta tag 'em all!

"Tag what you see" would probably be better stated as "Don't tag what you don't see." As in, don't tag tsundere just because a character is canonically tsundere, only tag it if it's visibly present in the post. That sort of thing. It doesn't mean tag every inconsquential object in the background. Lots of people like to tag absolutely everything, but it doesn't help anybody. Nobody cares that there's an electric socket in post #1742238, for example.

The most important things to tag are the things that set the post apart from other similar posts. Appearance-based tags (hair, eyes, clothing, etc) are easy to add but they usually don't help the most in this regard, so I consider them the minimum when I tag. Tagging a Hatsune Miku post with aqua eyes and twintails doesn't do much to distinguish it from the other forty thousand Miku posts.

So beyond appearance, the most important things are any actions the characters are doing, poses or postures, facial expressions, gestures, the location or setting of the image, and artistic techniques or the way the image is composed.

Can we add MagicalAsparagus' first reply to the howto:tag? It's currently long and confusing. In all honesty, it didn't help much when I was a beginner. I learned mostly from my own posts' tag history several days after posting

evazion said:

Tagging a Hatsune Miku post with aqua eyes and twintails doesn't do much to distinguish it from the other forty thousand Miku posts.

I can't quite agree with you. Maybe tagging Miku with twintails doesn't distinguish this particular image, but it helps to distinguish posts where she has no twintails, especially those which don't have an alternate_hairstyle tag.

Though if someone is going to change something in howto:tag wiki, I'd rather they added evasion's last paragraph about how posture, setting, actions and artistic techniques are important.

MagicalAsparagus said:

I can't quite agree with you. Maybe tagging Miku with twintails doesn't distinguish this particular image, but it helps to distinguish posts where she has no twintails, especially those which don't have an alternate_hairstyle tag.

I don't mean that it shouldn't be tagged. Just that it's the minimum and you should try harder if hair/eye/clothing tags are all you can come up with.

post #1755795 is an example of the kind of post I have in mind. It's a good post, but impossible to find because it's minimally tagged with stuff *every* Miku post has. Currently it only has aqua eyes, aqua hair, long hair, twintails, tank top tags.

The most interesting things about this post are the composition and art style, and the fact that her outfit is different than usual, so that's what should be tagged.

So first I'd tag bare shoulders, coat, casual, and maybe alternate costume, because those are the aspects of her appearance that differ from the norm. These things are more valuable than tagging just eyes and hair.

Next I'd add 1girl, solo, looking at viewer, bust, and simple background. These are all part of the image's composition, and composition is important because it helps distinguish between the thousands of posts where a character's physical appearance is all the same.

Last I might add flat color, because the art style is the most distinctive thing about the post to me. I'm not 100% sure if it qualifies because it's not completely flat, but the point is that it's something that's very distinctive so it's a lot more valuable to tag than basic appearance tags.

So overall, I'd say to ask yourself what makes the post stand out to you. Why did you upload it? What sets it apart from other similar posts? Once you're past the obvious things - Miku has aqua eyes, Miku has twintails, etc - those are the things you should focus on trying to tag.

I tagged the image and then read your post. I hit most of those :D Also, it's not tank top, it's camisole.