I was having this problem too. On the advice of a friend - for whom this worked! - I started a policy of "if it's left out, it gets put away until ALL the toys are put away every night". Well, my little bright spark took one look around, picked up a couple of toys, and said "You can put the rest away." 
Then it became a huge struggle. Until one day, she figured out that she could get into our loft (accessible via a ladder) that is never ever visited by guests (except my mom, who is pretty used to kid mess). Instantly I moved ALL her toys up there and told her she could tidy them up or not as much as she wanted, but I wasn't going to be going up there to find stuff when she lost track of her little 3-legged purple frog or whatever. I would *help* her clean up whenever she liked, and we could work out a storage system that she could use, but she had to pitch in.
I have to say that so far, it's not exactly a rousing success. She does occasionally complain that she can't find something, but usually after asking for help she'll just go back and keep looking. She's shown no inclination to tidy.
And you know, I'm not such a fan of the tidying either. I like the house *being* tidy, so I do it, but I get annoyed at every little thing I pick up. I'm sure this is genetic. So, I really doubt that at this stage in DD's life - she is just 3 - there is anything I can say (that's not threatening or coercive) that would get her to clean up. I will keep mentioning it, every time she can't find stuff, and keep modeling tidying behaviour, and keep encouraging DH to tidy up HIS stuff, and keep talking about why a tidy house is nice and how we all benefit from it, but TBH I'm not thinking that this approach is going to pay off in any major way for another few years. In the meantime, DD is starting Montessori preschool in September, where people she won't be so comfortable sassing will encourage her to tidy up, and the mess at our house is stashed away where I don't have to see it.
(Or not. I just turned around from the computer - there are DD's clothes strewn about the living room, her runbike lying on the floor, my magazines all over the place, the placemats from the dining table all over, the pillows from the couch on the floor (that's the dog's fault) and several cups and bowls all over. Sigh.)
Then it became a huge struggle. Until one day, she figured out that she could get into our loft (accessible via a ladder) that is never ever visited by guests (except my mom, who is pretty used to kid mess). Instantly I moved ALL her toys up there and told her she could tidy them up or not as much as she wanted, but I wasn't going to be going up there to find stuff when she lost track of her little 3-legged purple frog or whatever. I would *help* her clean up whenever she liked, and we could work out a storage system that she could use, but she had to pitch in.
I have to say that so far, it's not exactly a rousing success. She does occasionally complain that she can't find something, but usually after asking for help she'll just go back and keep looking. She's shown no inclination to tidy.
And you know, I'm not such a fan of the tidying either. I like the house *being* tidy, so I do it, but I get annoyed at every little thing I pick up. I'm sure this is genetic. So, I really doubt that at this stage in DD's life - she is just 3 - there is anything I can say (that's not threatening or coercive) that would get her to clean up. I will keep mentioning it, every time she can't find stuff, and keep modeling tidying behaviour, and keep encouraging DH to tidy up HIS stuff, and keep talking about why a tidy house is nice and how we all benefit from it, but TBH I'm not thinking that this approach is going to pay off in any major way for another few years. In the meantime, DD is starting Montessori preschool in September, where people she won't be so comfortable sassing will encourage her to tidy up, and the mess at our house is stashed away where I don't have to see it.
(Or not. I just turned around from the computer - there are DD's clothes strewn about the living room, her runbike lying on the floor, my magazines all over the place, the placemats from the dining table all over, the pillows from the couch on the floor (that's the dog's fault) and several cups and bowls all over. Sigh.)
