If you're speaking to an audience, don't gaze aimlessly around the room.
Instead, focus on a few people. Your eyes will show whether or not you believe what you are saying. Gazing aimlessly signals a lack of confidence in the topic.
More Social Tips
Pause frequently when speaking publicly.
Pause when you have said something you believe is important and as a way to let listeners digest the details.
When filming a special event for someone else, try to remain silent.
Not only will your future self thank you for not recording the cringe, the person you are filming for probably doesn't want it on there.
When giving a high five, look at the other person's elbow.
Guaranteed to make contact 99% of the time.
When learning a new language, find the top 100 most used words to start with.
Those words make up the majority of everyday speech, and should help you create a nice foundation to expand upon.
Praise publicly, criticize privately.
For example, if you are invited to a private social event through email, SMS, and intend to go, send an acceptance to the entire group. If you aren't attending, RSVP privately.
Knowing when to be quiet is an important skill in life.
Don't feel obligated to fill every silent moment.
Pay attention to how your co-workers treat waitstaff.
It's generally a good indicator of how they'll treat people they feel they have some power or control over.
At a party and don't know anyone? Introduce yourself to the host.
They can introduce you to other people and it scores you points so you get invited back.