Stop lecturing. Stop preaching. Close your mouth and listen to what they're saying.
2: Understand that they feel love
Let them grieve the loss of a boyfriend or girlfriend without telling them that it was 'puppy love' or a 'crush'. It was real love to them. Don't minimize their feelings.
3: Realize that texting is the new talking
Like it or not, this is how teens communicate. Don't tell them it's ridiculous and isn't real communication.
4: Stop pressuring them
Teens are under enormous stress to take advance placement classes, achieve above a 4.0 GPA, be the star on their team, qualify for the college you want them to attend, take SAT and ACT exams, etc, etc. All to avoid disappointing you. Kids crack under unrelenting pressure. There is a difference between encouraging your kids to be the best they can and pushing them to unrealistic and unhealthy expectations.
5: Don't make them responsible for your happiness
Find your own interests and your own life and be happy with that. Don't make your child the end-all of be-all of your satisfaction with life.
6: Let them fail
Don't rush in to fix what they've messed up. Don't do their homework because they put it off. Don't talk to their friend's parent in an effort to mend a relationship. Tell them in advance what the consequences are for certain behaviors and then enforce them. Babe Ruth said, "Every strike gets me closer to my next homerun", and he did pretty well.
7: Trust themunless you have a reason not to
Don't search their room for a journal or stalk their social media to spy on them. Let them know you trust them unless they prove to be untrustworthy. Set limits and realistic expectations of behavior and then trust them to follow through. If they don't, let them know that they didn't show that you could trust them on this particular item and tell them how they can earn that trust back.
8: Say you're sorry
If you've done something wrong, apologize. We expect kids to apologize to us, but you would be surprised how many parents don't feel a need to fess up to their kids when they are wrong. Saying you goofed up goes a very long way in your teen's eyes.
9: Don't be cool
You don't need to be their pal. They already have pals. You need to be their parent. It's not necessary for you to be able to sing the latest song while driving them to school (please don't), but it is essential that they know they have a strong and reliable parent they can turn to. Stop trying so hard. Do you really want to be 16 again?
10: Accept who they are
They are not miniature versions of you. They are their own person with unique talents and ideas. They are not their older sister or you when you were their age. They may be difficult. They may be a dreamer. They may not make the choices you think are correct but really, don't you just want your child to be healthy and content? Does any of the other stuff really matter? At the end of the day, you want an enduring relationship with your child. Blue hair or a double ear piercing may not truly matter if your child can come to you for solace and know that there's always one person in the world on their team. Let it be you.