5. Be on time. You knew I was going to say that, didn't you?
6. Fix it and forget it. Sure, take time to look nice. Shower, do your hair, fix your makeup. Feel confident about how you look. And then here's the key: forget about it. Focus on other things than how you look.
7. Save the day with laughter. A great-grandma Brockbank classic phrase, her mothering motto can apply to and lighten pretty much any situation.
8. Everyone feels shy/awkward/insecure sometimes, especially in new situations. Introduce yourself, smile, shake hands, and make eye contact. (And don't be one of those people who pretends not to see someone they know...just go say hi! It's the kind, right thing to do 99% of the time.)
9. Any sentence that begins with "no offense but..." or "I hope this doesn't offend anyone..." probably will. Be thoughtful about whether you need to say it at all.
10. From a reader: start a simple little notebook to record your own health information, keeping a basic, running log of everything from doctor's visits to what cold medicine works best to allergy/hay fever patterns to medicines. Keep those immunization & check-up reports handy, too. You'll need those over and over again: school, jobs, travel.