I have a tip I thought I'd share with you all. If you have any of your own it would be nice to see them all 
My 12 year olds bedroom was always such a mess. Clothes, towels and rubbish on the floor, she never puts anything away. I was having a chat with my sister one day and she gave me 'the four step' process of room cleaning for older kids.
It worked really well and my dd even said 'that was easy mum' so here it is: (child does the work, mum instructs)
- Take everything off the bed and make it
- Put any clothes on the bed (clean or dirty) then sort
- Put anything that's not rubbish into a laundry basket
- Put all the rubbish off the floor into a bin bag
At this point I Hoover (kid could do if you prefer) then kid puts her stuff away from the laundry basket (I don't mind how long that bit takes-as far as I'm concerned job done)!
If you have any tips to share, it would be a fun read!