How to handle students not returning borrowed equipment?

I add an assignment in the grading system with a single point: "returned all borrowed equipment."

I don't actually use it in the calculations, but seeing it in the gradebook (which students can access) encourages compliance.

I can see two solutions here:

1. Deter students from borrowing or walking away with equipment

If safety is not a concern, you could require a shoe as a deposit. No student will get very far after class without realizing what they're missing. It will save you having to remind your students to return said items.

You could also take a tally of all loaned items and release the class only when all have been returned.

Another solution is for the replacement equipment to be clumsy, comical, or embarrassing. Giant calculators might get the job done, but they won't be inadvertently taken out of class and you might not see many repeat customers.

Unfortunately, any deterrent besides loudly pronouncing at the end of the class "please return anything you have borrowed!", or perhaps taking a tally, may be difficult to implement without giving a distinct "I don't trust you and am going to treat you all like children" impression.

2. Stop lending out equipment they are supposed to have.

A more cynical point of view is that university students should be intelligent, responsible, and well enough prepared to bring any equipment that is either listed as a course requirement to have, or is generally expected (e.g. a calculator, stationery).

Your students are probably less likely to prepare properly for class precisely because they know you have spare equipment. If they're supposed to have their own stuff, make it the students' own problem if they forgot. They will only learn if failure carries consequences. If you abolish your loaning policy, I suspect the fraction of students coming properly prepared will quickly, and significantly, improve.

Unfortunately I do not have enough rep to write a comment on Moriarty's answer, but I think that it is most likely because of absent-mindedness in the part of the student.

I wanted to comment the following idea if you're lending out something like pens: My mother used to work with students who would need to come in, go through a long document and sign it before leaving. She would go through an enormous number of pens, as the students often just popped them back into their pockets by accident.

She came across the idea of flower pens (gluing a big fake fabric flower to the end of the pen) and implemented it on the pens in her office, and she said that suddenly her pens stopped disappearing - since they were now tricky for the students to mistake them for their own, or accidentally stuff them in their pockets.

Depending on equipment you could try other things (I imagine you could spray-paint some things in bright neon or shiny colours, attach big tags or tassles to the items) to make them stand out a little more.

(A sample pen: http://ideasforfrenchclass.blogspot.com/2010/09/flower-pens.html)