them:

• compliment them (or other people)
• copy their behaviour
• emphasize shared values
• let them talk about themselves
• tell them a secret
• use their name
• touch them
• ask them for a favour
• ask their advice
• make a little bit of eye contact

self:

• be vulnerable
• display a sense of humour
• reveal your flaws occasionally
• smile, be positive, happy
• power-pose (for self-confidence)
• show the palms of your hands