Being assertive means being able to express your point of view in a way that is clear and direct, whilst still respecting others and their opinions.  Communicating in an assertive manner can help you to minimise conflict, to control anger, to have your needs better met, and to have more positive relationships with friends, family and others. Assertiveness is a style of communication which many people struggle to put into practice, often because of confusion around exactly what it means. Sometimes we often confuse assertiveness with aggression because it involves sticking up for yourself; however the two are actually quite different. Tips for being assertive:
Deliver your message directly to the intended recipient.
Use statements that make you want, think, and feel as clear as possible.  For example, “I want to…” or “I feel…”.
OWN your message.  This is where the “I” language comes into it.  Rather than saying “you should…” try saying “I would really like it if you…”.
Ask for, and encourage clear, specific feedback.
Be specific and objective when describing the behaviour of the situation.
Don’t use generalisations such as “you always…” or “you never…”.  Focus on the most recent case, saying “I noticed today you….  When you do that I feel …”.  Using behavioural descriptions allows you to avoid using labels that hinder the other person’s acceptance of your message.
Avoid ‘why’ questions to further reduce the likelihood of the other person becoming defensive.
Avoid becoming emotional when describing how it makes you feel.  It may also be appropriate to provide some explanation as to why the situation or other person’s behaviour makes you feel that way.  Focussing on your feelings has two important effects:  it invites the other person to see things from your point of view and, unlike statements of the facts as you see them; your own feeling can not be disputed.  This is especially true when you say “I feel…” rather than “You make me feel…”, to which they may reply “Well I don’t mean to”.
Be specific about the action required from the other person, taking into account the rights, needs and feelings of the other person.  If necessary and appropriate, clearly describe the consequences of the other person’s behaviour not changing.
Do not be apologetic about your feelings, rights or opinions.  Say “no” to unreasonable requests, also without being apologetic.  Even offering an explanation is optional.
Only address one issue at a time, rather than listing everything you believe the other person has done wrong.
Be sure to acknowledge both the feelings shown by the other person, and any issues they bring up, then immediately return to your point.
Maintain eye contact (if culturally appropriate) and use tone of voice and body language to reinforce your message.
Conflicts often occur over differences of opinion, facts, perceptions or values. While no one approach or method of resolving conflicts covers every situation, developing the skills of assertive communication can be useful in a variety of conflict situations. You can try the WIN Formula below. By using this technique, you can focus more easily on the real issue, express how it is affecting you and describe what you would like from the situation.
W = WHEN       When you… (state specific behaviour you don’t like)
I = I                     I feel… (express a feeling or thought)
N = NEED          I need/want (specify what you want to change)