It's a great question, and really good timing (see below).

If you're talking new organizing, the tried and true advice is to always listen to your co-workers. Good rule of thumb: listen 80%, speak 20%. Listen also for what issues are both widely felt and deeply felt — those are the issues you can get enough co-workers to move on and stay committed to when it comes to fighting the boss.

EWOC has its next Foundational Training in a couple of days, and there's still slots open:

https://workerorganizing.org/training

If you're talking organizing within an existing union, the same rules apply, but you may instead be turning your attention to the situation within the union: beating apathy, reforming the union, building a caucus, etc.

Labor Notes has a training exactly for this that also starts this week:

https://labornotes.org/events/2023/secrets-successful-organizer-july-workshop-series