An assertive person takes full responsibility for herself and her actions. 

• Seek self-control, be fair and reasonable, take on the part of the problem that belongs to you, and keep the rest of the problem where it belongs--with the difficult person.
• Set limits and stand up for yourself so others won't take advantage. 
• Use "I" statements, not "you" statements (these tend to lead to attack and blame).

• Maintain comfortable eye contact. 
• Remain open-minded.
• Pay attention to non-verbal signals as a way of reading the person's feeling state.
• Use an "I" statement of feeling. Ex: "I feel like this decision violates our trust."