As a person who at one point had six children 11 and under, it is very vital you teach them to pick up after themselves. In my home if you are old enough to make a mess you are old enough to clean the mess.
A week or two before birthdays and about a two to three months before Christmas, I have the kids go through their toys and pick the ones they are willing to give away and/or throw away because we always had to make room for new things by getting rid of old things.
The kids are now all grown and they are still really great about gifting things away and throwing things out. The main little toys that were always about were Lego, Barbie accessories and Matchbox and Hotwheel cars. I must also confess there were occasions I would step on something, hurt my foot and then angrily toss it. Great times and great memories. It flies by so fast. Enjoy them while they are young, laugh often, and have fun.