Fairpoint
A fair point at a time.
Tiny, opinionated quizzes on how to use Slack like you mean it. Take one, learn one habit, share with whoever needs it.
Most Slack etiquette advice is vague ("use threads more"). Fairpoint is concrete: each site takes one specific habit, walks you through 40 real scenarios, and shows you the failure mode for each wrong answer.
Each lesson runs in about 5 minutes.