For storing stuff in an apartment, you might keep an eye out for dual-use furniture.

I use a vintage trunk as a coffee table.

Those underbed storage boxes are good for food storage. If your beds aren't tall enough, just boost the height with wood blocks.

Closets often have one shelf when a second one above it would be better.

If there is room somewhere, a free-standing pantry could be useful.

If you've got a large living room, consider stacking boxes at one end or corner and setting up screens in front of them to make an artificial wall.

Dog people use large crates as end tables, covered with designer fabric. Most people never notice. You could do the same with boxes of survival gear.

Have the door locks re-keyed and give the manager a copy.