(Disclaimer: not all of these I agree with.)

• Forgetting the names of people you meet
• Repeating yourself
• Being unfriendly
• Not holding eye contact
• Rambling
• Excessive throat clearing
• Forgetting what you’ve told someone
• Gossiping
• Finishing other people’s sentences
• Interrupting others
• Monopolizing the conversation
• Saying “ummm” and “ahhh” frequently
• Picking fights
• Being overly critical
• Being argumentative
• Being a know-it-all
• Bragging
• Name dropping
• Overuse of slang
• Exaggerating