Just spent two days working to straighten a room . The answer is not to let it get out of hand . Invent a system that works for you and think of all that set - make sure that 's where you really want it . Then,
I don't know what to say about getting it clean, so I'll put that responsibility on you. :)
Do you need to get organized? Buy some plastic bins and whatnot to organize things. Buy units to put in your closet to organize that as well. Slide containers under our bed for storage no one can see.
Every night, before you go to bed, take 10 or fifteen minutes to tidy up anything that's out of place.
Make sure to keep your dirty close in a hamper, of course. Most of the time when my room is messy it's 95% clothes! Haha.
Hope this helps.
You're going to have to go all out on this one. This means, dedicate an entire day to organizing your room from top to bottom. Sort drawers, clean floors, dust shelves, etc. and find an easy, convenient place to store those things which usually get out of place.
I can assure you that after spending hours cleaning and organizing your room, you wouldn't dare make the slightest mess in the future.