Dear Jilly -
That is great that you have basements! I agree that if you haven't used something in a few years it's at least worth looking at. Sometimes there are legitimately things we only use every few years. But many times it's a sign of clutter.
Our basement is still an untouched, giant mess. It frustrates me, but we have made a lot of progress on the upstairs rooms. So I'm focusing on priorities. We have done quite a lot of cleaning out and giving away and organizing in the main household areas. Still a mess, but taking those small steps. The basement will have to wait until we get through this other stuff.