Short answer: bedding, lighting, curtains — in that order. All three are reversible, all three move with you, and together they change a rental bedroom more than paint would.
Why the bed is the whole lever
A rental gives you beige walls, a floor you did not choose and a light fitting you would not have bought. What it does not control is the largest surface in the room, which is the bed. In a rented bedroom the bedding is not one element among several — it is the only large-scale colour decision available, so it carries the weight that walls carry in an owned home. That also means the usual advice to keep bedding neutral is often wrong here: if the walls are already neutral by decree, the bed is where the room's character has to come from.
Lighting: the cheapest transformation available
The overhead fixture in a rental is almost always cold, central and unflattering, and it is also almost always the only light. Two plug-in lamps with warm bulbs — one bedside, one in a corner — do more for how a room feels than any other twenty dollars in this list. Warm-toned bulbs make beige walls read as cream rather than as institutional, and low light sources make a room feel taller. Nothing is drilled and nothing is left behind.
Curtains without drilling
Tension rods inside the window recess hold ordinary curtains without a single hole, and floor-length curtains — even hung inside the recess — change the proportions of a room more than their cost suggests. If the rod truly cannot be fitted, adhesive hooks rated for weight will carry a lightweight panel. Choose a colour picked out of the bedding rather than matched to the wall; that repetition is what makes an assembled room look designed.
What to do about the carpet
Landlord carpet is usually the hardest thing to live with and the easiest to partly solve: a large flat-weave rug over it, held with a non-slip pad, covers the visual field where you actually walk. Large is the operative word — a small rug marooned in the middle makes the floor look worse by drawing a frame around it. It also rolls up and travels, which a paint job does not.
Things that come off cleanly, and things that do not
Worth knowing before the deposit conversation. Adhesive strips rated for the weight, removed slowly and with heat from a hairdryer, come off most painted walls without a mark. Removable wallpaper is genuinely removable on sound modern paint and genuinely not on old distemper or freshly painted surfaces — test one strip in a corner and wait a week before committing a wall. Command hooks left up for years are harder to remove than ones taken down at month six. And anything involving screws, however small, is a conversation with the landlord rather than a decision.
Smell, light and the two senses rentals get wrong
Rented rooms often carry the previous tenant's smell in the carpet and the building's light through thin curtains, and both affect how the room feels more than any object in it. Airing the room daily for a week, washing every textile you own on arrival, and lining curtains — even with a cheap supermarket blackout liner clipped on — deals with most of it. A room that smells of nothing and darkens properly at night reads as yours far faster than one with better furniture and neither.
Everything else should be freestanding
Mirrors leaning against the wall rather than hung. Art propped on a chest or a picture ledge held by adhesive strips. Plants on the floor rather than brackets. The rental constraint quietly enforces a discipline that helps most rooms anyway: fewer things, each of them substantial. A single large leaning mirror beats four small hung frames in almost every rented bedroom, and it returns light into the room as a bonus.
Choosing bedding that survives the next move
Rentals change, and the bedding will outlive this one. Two practical consequences. First, size for the bed rather than the room — a Queen is a Queen in the next flat too, and the size guide covers measuring properly. Second, prefer designs that do not depend on the current wall colour: a strong quilt on a cream wall works in most rentals, whereas a quilt chosen to match one specific landlord's feature wall works exactly once. Sets start at $99.99 and arrive as a quilt with two shams, which is the whole room's colour scheme in a single box.
The order to spend in
If the budget arrives in pieces: bedding first, because it is the largest surface and the biggest change. Warm bulbs second, because they cost almost nothing and alter every other decision. Curtains third. Rug fourth. Everything after that is optional, and in a small rented room — the usual case — most of it is better left out entirely.
What you will get back at the end
Worth stating plainly, because it changes how much a renter should be willing to spend: everything in this list leaves with you. The bedding, the lamps, the curtains, the rug, the mirror. The only thing left behind is the adhesive hooks, and those cost a dollar. A rented bedroom done this way is not a compromise version of decorating — it is the same decorating, with the furniture of it chosen so it can be lifted out in an afternoon.