With teenagers it is very simple, however you have to fight the whole 'I know best' thing. Curfews are easy as we live in a city centre, it is not safe to walk the streets at night so she needs to be in before dark, and if she goes out she needs to go somewhere, no hang round a park. This is discussed and agreed, she knows what's what and curfew times are agreed, and if she is going to be late she lets me know, constant texts and updates etc.
With her room - have come to the conclusion that if she wants her room to be a pigsty she can. As long as she keeps the rest of the house tidy, and she does her share of the chores as all members of this house do, she can live out her Rik from the Young Ones fantasies in her bedroom.
Homework - it's her homework, it is up to her to be mature enough to schedule revision and complete her homework. It is her life - if she fails her exams she will not get into college and get into her chosen career. I am not standing over her saying 'do your maths'. She has got to learn to manage her own workload, she is nearly an adult now, I am not doing it for her. This has worked well - she is a conscientous student and is on course for good grades at GCSE.
Strangely enough, she is hoping to join the RAF at 18. She goes to cadets and LOVES the strict discipline, and the marching and drill and being yelled at. Her bedroom is a mess yet she spends hours polishing shoes and ensuring her uniform is correct, and when she goes on camp gets high points for her immaculately made bed!