I am frequently lending my supplies to students, teachers and other classes. Last year only some of the things I lent out got returned so I knew I needed an easy system of tracking where my things were going.
First: When I get a request to borrow something I immediately write where the item is going on my whiteboard. e.g. Scissors – Smith Room 205. If it is not in plain view I will forget where my resources have gone to. If it is a long-term loan (DVDs, Binders, Units, Books) I usually write it in my daybook in a special section for loans.
Second: I used coloured duct tape to differentiate my items from others. This could also be done with washi tape, but coloured duct tape was cheaper and more came on a roll. Now if things do not get returned I can go straight to the classroom and identify what resources are mine and what belongs to that classroom. This also helps students identify which is their personal items and which belong to the classroom.