I'm a great believer in luck your battles and the more 'rules' you impose the more there is to fight against.
I can see why secondary pupils do revolt and ignore some rules. We are meant to live in a country of free speech - we are not in a dictatorship.
My school managed to maintain high standards when I attended because rules allowed for plain nail varnish, minimal mascara and a plain pair of studs and simple chain and a reasonably sized watch. Therefore we could chose all or some of the above to have some level of ownership over our own personal appearance.
Skirts had to be of a certain length but style was totally free choice.
Trousers had to be boot leg but again the style was free choice.
It was the 2nd best school in the local area and the only one better was an indi. It remained an ofsted outstanding school throughout my attendance.
It had high expectations but didn't need to rule by punishment and isolation.
Ds secondary are the same. And I love the fact PE uniform is school polo t shirt and then navy shorts or tracksuit bottoms with a navy jumper or zip up. Trainers are whatever you chose (neon colours seem to be the fashion item of choice ATM!) and they allow girls to wear Lycra sports leggings. They have the best sports teams locally and I believe it's because they focus on teaching the subject - not on clothing! Skirts aren't generally a problem length wise (a few try it on!) but then they can have any skirt as long as it's Cotton and knee length. (Think they can have so much above the knee?).
They allow some jewellery and reasonable make up.
Most of the pupils carry backpacks and wear brogues type shoes for girls and the standard one strap Velcro (kicker style shoe) for the boys.
Boys must wear black/grey socks with mid grey straight leg trousers. They allow them to choose which style.
Everyday I take ds to and from school and I can honestly say the kids look individual yet like a school with good uniform standards. Gcse results are extremely good and pastoral care at the school is amazing.
I believe the pupils respect the rules that exist because the school respects them and puts their emotional well being at the core of everything they do. The pupils want to represent the school because they are proud of it not because someone tells them exactly how to dress regardless of their build or height.
I'm an advocate of uniform but I think it's gone too far in many schools. Even our local independents (quite a lot around here!) are less dictatorial over uniform than the local academy.
Ironically the academy is the school is the greatest uniform issue and worst results! (And it's gone downhill since they started this so it isn't 'why' they are doing it iyswim?)