One of the best things a teacher can do is to be real. Let your true personality show as much as possible when you are in the classroom. If you are the serious type, don't try to be silly and fun in the classroom just because you heard that this style is popular with students.
Having popularity as a goal is definitely a big mistake. Your top priority as a teacher is not to be liked. It's not even to be happy. Your first objective should to serve your students. Trying to be popular or cool will inevitably lead to you compromising what is best for students to help fulfill your own needs of being liked. Always keep this in mind and everything else will usually fall into place.
Have enough of a life that you don't have to rely on your students liking you to feel good about yourself.
Shape your teaching personality out of the real you. There is nothing wrong with getting ideas from other educators, but your main identity as a teacher should come from your true personality. Following this rule will make it much easier for you to relax, enjoy yourself, and feel good about what you have done at the end of the day.