Parents and teenagers are always going to disagree about some things. It's simply the nature of the beast.
You, as the parent, are the half of the relationship with experience, who knows the limits, who wants to protect your child and who hopes to help guide him or her in positive ways.
Your teenager is the half of the relationship who is not only dealing with physical and emotional changes, peer pressure, and the normal developmental growth of desiring more independence, but who has to also put up with all the rules, "those totally unfair rules", that you, the parent tend, to impose.
Yes, some conflict between parent and teen is inevitable, but there are things you can do to minimize the disagreements.
Start by remembering that you are the adult. Stay in control. Your teen may be trying to act grown-up, but often realizes deep down that protection and guidance are needed. Children want to be reassured that their parents are still in control, helping to guide the teen's life and development.
Most importantly, learn to listen! It’s easy to be the busy adult, ignoring or misunderstanding your child. Instead, remember your own teen years and try to understand what your child is feeling and trying to communicate. Really listening to your child, understanding and respecting what is being expressed without being judgmental, can help strengthen and improve overall communication.
You also want to set limits, but limits with options. Your teens may argue, but they also understand that there are always limits to what is allowed. Instead of being a dictator, offer options whenever possible that keep things within limits but do allow your teen some freedoms. Choices are important to a growing teen, even if sometimes the wrong choice might be made.
You also want to build a relationship with your teen, not one where you are your teen's best friend, but rather one as an adult who can be depended upon and trusted. Get to know your child, his or her friends, interests and feelings. Let your child know that as an adult you have your own feelings, values and rights.
As teens move toward adulthood there will always be some conflicts and disagreements. But by respecting your child's growing maturity and independence, and showing you're aware of those changes, you can help build a more positive relationship for both of you.