What finally saved the day was trying out screw hooks from
https://arthangingsystems.com.au/product/2mm-mini-screw-hook/ — these tiny hooks were super easy to install and didn’t damage the walls. They're surprisingly strong and give the space a clean, gallery-like look. I’ve now used them all over the apartment, and even the landlord was impressed when he saw I didn’t wreck the plaster. If you're renting, these are a must-try.