Have an informal 'meeting' in the lunch room

Pass out a leaflet

Set up an information table in the lunch room

Have short meetings right after work, maybe in the parking lot

Have a button (or sticker) day

Have a union hat or T-shirt day

Have a RED day (or a BLUE day)

Get lots of people to file individual grievances

Get people to sign a petition or group grievance

Get a big group to deliver a petition or group grievance

Get lots of small groups of people to ask the boss when the problem's going to be solved & keep asking until they get an answer.

Have a pep rally in the lunch room

Put daily notices on the union bulletin board to keep people up to date

Go to the top (CEO, board of directors, shareholders) with letters or petitions

Explain an issue or event with a skit in the lunch room

Have a prayer meeting in the lunch room

Have a rally or informational picket line outside the plant before or after work

Use cartoons, adapted to the problem, to add a little humor

     'Write up' the supervisor or other management, and 'call him in the office' (or lunchroom) to present the warning (even if he doesn't show).

     Ring bells or blow whistles or shake soda cans full of pebbles at appropriate times (when the boss does something wrong, or every time the problem happens, or every hour or so as a reminder)