This post has 30 ways you can be a marketplace minister. Some of my favorites include,
1. Instead of eating lunch alone, intentionally eat with other co-workers and learn their story.
3. Make it a daily priority to speak or write encouragement when someone does good work.
11. Make every effort to avoid gossip in the office. Be a voice of thanksgiving not complaining.
24. Invite your co-workers in to the service projects you are already involved in.
29. Keep small candy, gum, or little snacks around to offer to others during a long day.