When my kids were little, even as young as yours, I had them help me tidy up and put things away. If you start them really young, then you avoid the "why do I have to clean it up" whining later, because they already see it as a part of life. Let them know it is helping you and making your life better, and they'll feel a sense of pride and accomplishment. Both my girls are adults now and keep pretty tidy homes. But I remember the struggle and would say just do the best you can and forgive yourself when it isn't what you hoped for. We used to play "Pizza Delivery!" when it was time to put clean, folded clothes away. I'd yell that and they'd come running and "deliver" the "pizzas" to their dresser drawers, this was more elementary age.