Even though it seems like teens start ignoring their parents at some point, they're still profoundly influenced by their parents' behavior. So as a parent, you will be a role model. The issue is what kind of role model will be you be: positive or negative.
The first step to being a positive role model for your teen is to focus on making good, ethical choices in your own life. Role models often teach most by example, rather than by lecture. So if your behavior contradicts the life lessons you're trying to discuss with your teen, your words will likely fall on deaf ears. Teens can be especially interested in understanding how you make decisions or respond to your own mistakes. During adolescence, your teen does start to see you as a fallible human being, so you aren't telling secrets if you let your teen know you've struggled with a decision or made a mistake. Instead, take that experience to give your teen an example of how he/she can manage his/her decision-making processes.
Since you do want your words, as well as your actions, to influence your teen, you should make an effort to communicate well with your teen. This means doing at least as much listening to your teen as talking to him/her. If you constantly respond with judgment or condescension to your teen's concerns, he/she will stop sharing them with you and not be interested when you do have something to say about them. So make sure your teen knows you're available to talk when he/she wants and that you'll be a good listener when he/she does come to you.
You might also want to model some specific behaviors for your teen, such as meeting all types of people with kindness and acceptance. Your teen will also note how you act under stress or when you're angry: Are you short-tempered or do you react in nonaggressive ways?