A friend lost most of a deposit to a "cleaning fee" that appeared from nowhere. It's made me nervous. How do you protect yourself so the deposit actually comes back?
Photograph and date everything on move-in, including what's already damaged, and send it to the landlord so it's on record. Boring; saves you the exact argument your friend had.
Check whether deposits in your country have to sit in a protected scheme — some do, and it changes your options in a dispute. The Housing section flags it per place.
Get every "we'll sort it later" in writing. If it's not in the contract or an email, it didn't happen when you're trying to get the deposit back.
A proper written inventory at check-in, signed by both of you. The landlords who resist doing one are telling you something.
Photos + protected-scheme check + written inventory. That's my move-in checklist now, thank you.