How do you teach “Tidy Up”?

One of my previous labs used to tidy up his toys from the garden, he’d bring them in and put them in the toy box before his walk. I have absolutely no idea how I taught it, it’s a nuisance as it was really useful. Obviously it was no help at all telling you that :rofl: .
I emptied Maisy's toy box and together we filled it back up one by one. Firstly I put the toy 'In the box', showed her how, guided her, then a treat when she did it. Her aim wasn't great at first but she got a treat for each effort. Now when we play 'In the box' she takes things out of the box just so she can put them back for a treat. Sneaky.