I'm generally not fixing cite errors, as I've moved to fixing no target errors instead.
Pages with reference errors
Pages with incorrect ref formatting
Pages with broken reference names
Pages with duplicate reference names
Pages with missing references list
No target errors are just more fun to fix:
Harv and Sfn no-target errors
These seem to have some common causes.
Process for whitelisting False positives
Useful tools:
Earwig's Copyvio Detector
Wikipedia Library
Wikipedia:WikiProject Guild of Copy Editors
For when you're being lazy
Accepted wiki behaviours;
Remember as long as you mention WP:BEFORE you can make as many asperions about a person's competence or motive's as you like.
Vandalism;
I can understand an IP address that makes one vandal edit, and never edits again. The urge to cause mischief is part of human nature. But why on earth do people create and account and then do the exact same thing? Even more baffling are LTAs, who seem to put a lot of work into causing minor issues that are reverted with minimum effort.