I found this on tumblr and I thought I should share it
How to be More Assertive
1. Use the word “I” instead of “You” as it demonstrates the speaker has self respect, and believes that their feelings and opinions should be heard.
2. Don’t stare the person out – but maintain steady eye contact. If you look to the side, look down or look away, it indicates discomfort or timidity.
3. At the same time, pay attention to your body language. Make sure that you seem open, and not hostile and aggressive. For example, your hands and palms should be open and relaxed, don’t point your finger, or wrinkle your face, don’t cross your arms, or look angry and tense.
4. Also, pay attention to the way you speak. Try and moderate your tone of voice; and don’t swear, use obscenities, or call the person names. However, don’t start to mumble or speak in a low voice as that can indicate a lack of confidence, and signal to the person not to take you seriously.
5. If you start to notice you’re becoming upset, then work on your breathing, and try and slow it down. Also, breathe deeply from your stomach – and visualise yourself as someone who is calm, strong, and being heard.
6. Remember that no-one else is going to stand up for you. You deserve to have respect, and to be treated well by others. Also, you have the power to establish boundaries, and to set appropriate limits on the treatment you’ll accept.