These easy things will make you a better person! I don't remember where I read this, but it's true: manners exist to make sure that everyone feels comfortable. Do your part to make others feel included.
  1. Always introduce people
    What is more awkward than being mid conversation with someone when their other friends come over, and rather than a quick 'hey _____, meet ____,' you're left awkwardly wondering if you should participate or pretend to look at your phone while they engage in a 10 minute conversation with a total stranger/their apparent best friend? Just introduce people! All will appreciate it, and maybe even make some new friends out of it.
  2. Don't talk about plans in front of other people, or if you do, invite them-- and do so like you want them to come
    Even (especially!) if you don't know them well. Nothing feels better than that reach out, especially if you're new in a group of well-established friends.
  3. Chew quietly, in small bites, and with your mouth closed
    Come on, now.
  4. When speaking to someone in what is not their first language, assume they are far smarter than they may be able to present themselves as
    I learned this one by being that person myself: trying to communicate in German, there were a million subtleties suddenly lost, and quite a lot that I could understand but not say. Remember this and speak clearly, but not condescendingly, to anyone learning your language. Remember, they're excited to practice!
  5. Be thrilled by any and every present
    A present is a token of love! I used to be so bad with this one, and still struggle with it-- even when I love a gift, it can be hard to fully convey that without paying attention to how I express that. Bubble over with excitement! It is so rewarding to see how thrilled the giver is that you're thrilled. And if you don't like it, exchange it later. Or if you can't, well, not showing your appreciation won't change that.
  6. Be thrilled to see people
    In the same vein as the previous one- people will always feel good to see that you're excited to see them. Show it! Often how happy we feel isn't quite communicated without our intention, thanks to our understanding of politeness as sometimes subduing emotions. That can be important-- but not here. Here, play those emotions up and act on them! Be warm, be welcoming, be a hug in human form.
  7. Let others know you're thinking of them
    Always better to reach out. Especially if it's been a while! Especially if it hasn't! Especially if they weren't an extremely close friend! Especially if they were! Especially if you're passing on a book or wisdom or etc relevant to something going on in their life! Especially if you're just saying hey, thinking of you lately! Again-- people are always happy to know that you're thinking of them, and more often than not, they were thinking of you too.
  8. Be on time
    BE. ON. TIME. I know- this one is tricky! One trick I use is to think of my leaving time as 10 minutes before it should be- because if I know I have to be in my car at 8:00, that translates in my head to having to be ready to get in my car at 8:00, which means I'm aiming for 8:00... Which means I'm more likely to leave at 8:10. Even when I'm aware of this thought process. Which is why in this situation, I aim for 7:50! Know thyself, outsmart thyself, fellow humans.
  9. Be kind
    Always. Unexpectedly. Extravagantly.