dear jsr1, welcome to hcm.
Do not try tellin ur daughter about the wrong things which she does. at this age, U need to reward her for all the SMALLEST good things she does. Try to be polite and humble rather than trying to be very strict with her. Try to behave like ur her friend who can understand her feelings and can be there when she needs a person. Do not keep on pointing her that whatever thing she does is always a NO in ur vision. Involve her in certain routine homely activities (cooking can be of some help) and encourage her in all her activities and find out what is she interested to do the most and try to involve urself in them even if it costs u ur time. Let her come to a conclusion that u definitely are a person who respects her secrets and make her feel more comfortable in ur company. Compliment her for all the small things she does and talk to her like someone of her age rather than trying to be a usual parent with a generation gap. this builds her confidence in U and lets her share her routine to U. if she tells U some things which according to u seems very boring, Yes, accept it and LISTEN to her. Keep urself in the shoes of a teenager and observe how is the lifestyle in today's teenager.
I would like to add one more thing here. Please advice her regarding safe relationships too. Please do take some time and advice her for her behaviour with the opposite sex too. Tell her to have an open mindedness and be friendly with everyone and keep a watch on her close contacts too. do not encourage on the use of cell phone as it has been practiced till now. Please keep a check.
Encourage her to talk to her friends in ur presence too and U should also converse with them quite often. Arrange for a small get together inviting all her friends and involve urself actively.
Respect her for each and every of her actions and try to make her comfortable.
thank You:-)