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.

A lot of great ideas!!! Many wives will appreciate the dressing up aspect for sure!

Interior decorators use vintage suitcases stacked for end tables.

Hide a large wooden box, with lid in plain sight as a toy chest. Distress it so it appears to be an antique for even more reason to have it even if there are no children to use it.

An extra hamper in the bathroom is a good hiding place for things that are protected or aren't harmed from the excess humidity. T-paper storage for example. Flatten the rolls and quite a few will go in a hamper.

Switch your storage concepts. Convert a closet into a pantry. Store clothing (especially seasonal items)under the bed instead of putting canned goods under there. Put those extra blankets and quilts between the mattress and box springs. If you have a spare bed, store all the bed linens under the bedspread. Who's to know that you have 4 sets of sheets on that bed? Using this approach may free up a linen closet for a pantry, or at least free up a good portion of it.

A large seldom used stock pot in the kitchen can hold a lot of stuff. Just put the stuff in gallon zip lock bags that can be removed when the pot is needed.

Cut down on excess packaging. For example, cut off all the excess cardboard on that pack of 10 batteries. In some cases, remove it entirely. A pack of razor blades takes up very little space after all the cardboard and plastic junk is removed.

If you have a dinning room table that isn't used, put a large tablecloth on it. Each one of the chair seats becomes another spot for storage, since the table cloth hides it.

Another hide in plain sight is to paint those gallon pickle jars. (Paint black first to protect the contents from light.) Using stencils anyone can "decorate" these for display. Those sold for decorator purposes bring big bucks, so why not use the real thing to gain some storage? Before I forget, those holiday popcorn tins (either re-painted or as is) can serve the same purpose.

Just some thoughts on finding space.
Lee