My 5 year old does the same thing. What I do is especially with toys and such, "throw them away".
Say if you wont take care of your stuff then you dont need it. No dont actually throw it away. You goto be sneaky, throw it in a clean trash bag and fish it out and hide it before any real trash gets in it. The thing is as soon as you throw away the first thing that they really like, they will be picking up everything. then once they know you will throw it away thats all you have to say and it should get picked up. With stuff like a jacket, they might say oh i dont care, then you tell her well you cant play outside or go anywhere without it so....