Be firm. Be consistent. Create a very clear roadmap that provides her with the consequences for bad behavior.
For example, with my 13 year old niece I gave her the following action/consequence list: If you back talk me, you will go to your room. You will not be allowed to come out unless or until you are ready to speak to me with respect. (And, when she does sass me, I very calmly say "Go to your bedroom, Vanessa. You can come out when you are ready to speak to me with the same respect you want me to speak to you with." I don't fight with her and I don't yell. It's not a negotiation.)
Lying: I told her that if she lies, she is grounded to her bedroom for three days. Period. And I don't care if it's a big lie or a little lie. Lying is NOT tolerated. And I don't care if she lies the day before Christmas; the day before a family trip; etc. She comes out for school, the bathroom and meals. Period. She tested this ONE time almost a year ago the day before we were supposed to go on a weekend trip she was looking forward to. (She thought we would postpone/ignore the punishment rather than inconvenience the entire family. But that didn't happen. We got a babysitter (in the form of my Dad) to enforce the punishment.)
If she skips a single class, I told her that I would accompany her to school for an entire day. If she skips/cuts an entire day of school, I would accompany her for an entire week. (She absolutely believes that I would do this (because I WOULD) and hasn't cut to date.
This really helped keep things respectful in our home. She respects us/we respect her. It's been a win-win. Vanessa's grades improved and she is happier and more content because she can predict the consequences of her actions. She's still a hormonal teenager, so of course she's going to screw up, but I survived my own adolescence so I'm sure we can get through hers!