do we have a set of guidelines for tagging/list of tags to use? if not, is it okay to and should i use another website's tag list and guidelines to tag images?

I do the plurality of tagging so maybe I can help out.

Couple of major things.

1. Tag the sex of people in the picture only. So if the picture has one dude, then use male and 1boy. If in that same picture the sex of the viewer is female, don't use female but instead use female_viewer. Similar phrases to female_viewer such as female_pov have been aliased to female_viewer. If the reader of the caption is actually in the picture, then don't use the viewer tags, and if the reader isn't actually involved in the caption, don't use the viewer tags.

2. Pairings are described by sex/sex. A caption that has straight stuff is going to be male/female, gay is going to be male/male, etc. Shit like yaoi and gay have been aliased to those tags.

Anything specific beyond that I can help with?