- Start out friendly when you're interacting with someone you've never met before. It usually works out well.
- Don't spew BS answers when you don't know something. Seriously. Just own up to your knowledge gap and see if someone else can help.
- Working in a print shop: set up a system to check your work, double check, and triple check it. You can fix mistakes in code, but it's a lot hard in print.
- Installing Windows 7 on new PCs for government employees: follow up as many times as needed. Don't assume it's anyone else's job to help you do yours. They have important work to do, and you need to work around them. Don't expect people to be eager to turn over their computer to a co-op student, even if they're getting a shiny new one.
- College catering kitchen: don't mistake pickled ginger for sliced turkey, even if you haven't eaten all day.