Melanie had written for some ideas to get littles off to a good start being tidy and responsible for their materials. I will start by saying this is an ongoing effort at our home as anyone who has visited can attest. Further, if I back off of my diligence IN THE LEAST, we are easily sent back to square one. So please don't look at the pictures of the little ones working nicely and assume they just 'do' this of their own volition each and every time. This is really a situation where you must control the environment.
My best advice is very NOT Montessori. We are in homes, not schools, and have to be realistic about our level of control. We are not directresses who can set up a lab environment and devote our days to nothing but monitoring said environment. And really, do we want to be that? Likely not. Real life is far richer. It does require some adjusting of ideology however so you don't come to despise the method for the trouble it is causing you.
In a classroom all materials would be displayed in open shelving for the children to choose from freely. The problem you run into at home is that many homes have far greater age ranges doing the choosing than would happen in a classroom. That means the likelihood of children choosing materials they cannot manage well on their own. It also means that they may access the materials when you are not available to supervise sufficiently, thus developing bad habits.
To prevent this I would opt for lockable cabinets or a lock on the schoolroom/activity storage area. Do not let them at the materials unattended. You will spend far too much time reteaching and restocking. In smaller homes we have used lockable garage cabinets. We have even kept these outside or in the garage when necessary. One thing in, one thing out was the policy. It worked well. We have a lock on the school/craft room door in this house. I can tell you honestly if it isn't locked or if a babysitter gets lax and lets them in there we DO have a mess. We have had messes of monumental proportions in fact. So it's important not to let that happen.
If they only have the opportunity to do the right thing, then the right thing is what is reenforced.
This applies to meal times (ie don't let them access food unless you are prepared to follow through with proper cleanup routines) and bedrooms (do they have a system for easy clothing storage which you monitor?) and so on. If not, think hard about culling to the pt where you can be on top of those routines happening reliably. Slowly, and only if you really think it will improve life in some way, add back more items.
Less is more.
So once you have pared down and gotten a handle on the stuff make a few trays or bags of activities. Take out a mat or rug and tell the child you have a game to show him/her. They may grab at it but ask them to watch and wait a moment while you demonstrate unrolling the rug, laying out the materials, and using them. Then replace them all in the proper spots. Ask them to tell you where the materials go. Walk them through the process. Then let them at it. When they lose interest gently guide them through the motions of putting things back. They may balk at first. Remain cheerful but insist they go back. Remember that the process is really more important than the activity itself as far as instilling good habits go. It doesn't take long for the habit to be set. It doesn't take long for it to be undone either so don't gather more supplies than you can easily be responsible for.
You get what you inspect.
Some of the latest pics of little people projects here. Very blurry - they were in constant motion : )