Our principal laid out all the jackets, etc on the stage in the cafeteria and had all the teachers parade their class by during the day. I'm not sure how well it worked, but at least it got the kids in the room. Usually kids don't realize they've lost anything until Mom or Dad has finally had it.

I was volunteering at the school today and sometimes I look in the Lost and Found and put labeled stuff in the lunch room near where that grade is eating. Then, they always find it. Problem is most parents don't label stuff or it will just say "Mike", for example, with no last name!!!
SHC

What about reminding the kids to pick up there coat/sweater/hat/etc! This has worked for us! Sure I am dreading going up to the school this afternoon myself to tackle ours BUT a poster on the door---nothing mean really helped.

I have noticed the kindregarten and fifth/sixth graders are the worst.

We also have a new service group this year and guess what these kiddos do....return lost and found stuff that are labeled!

***with our dress code, 99% of the lost items are navy blue hoodies. This has helped.

Yes, try to make everything visible to parents when they will be at the school. Our elementary school has 3-4 fairly deep bins and nobody likes digging through them. Our middle school, however, has a fabulous area and created a window display. It's like at a mall where thing are on hangers, mannequins, etc. Things are found very quickly there!

On the occasion when you have an event where parents are going to be there, put the stuff out on a rack or on a table where parents can see it. Might help a tiny bit.
SHC

I think we all have that problem. Its amazing what gets left behind unclaimed. We have a long coat rack with shelves that we use for lost & found. At the end of the yr. anything unclaimed goes to the salvation army. Maybe you could try an assembly where you hold up items left behind to be reclaimed or during lunch hour. Good luck.