Making a note of a few resources on AO3 tagging.
An (Incomplete) Guide to AO3 Tags by Lililoveschampagne (and fellow commenters) on Reddit
Tags are Tricky...a quick and dirty guide by mostlyinthemorning on Tumblr (The guide is in jpeg format; there's no text-only version.)
Comprehensive List of Triggers, Tags & Squicks by VeelaWings
Tags for Beginners by the mod of ao3commentoftheday on Tumblr. The additional tags part is particularly useful. She also posted a series of
How to AO3 tutorials.
I found most of these through
HP Fanfic Writers' Guild. They also reblog writing resources and HP fest announcements. The group itself is on Discord (
Discord Invite), and they hold writing workshops there. They are hosting a
dark & grey character workshop from May 17 to May 20. Have a look if you are interested.