21 Small Things That Make a Rented Flat Feel Expensive
Everything here is reversible. None of it needs a landlord’s permission, and all of it comes out with you when you leave.
Light: things 1 to 5
The single biggest change available to you, and the cheapest. Replace overhead bulbs with warm ones around 2700K. Add at least two lamps at table height. Never light a room from the ceiling alone – a single overhead source is what makes a room read as institutional rather than domestic.
If you do nothing else on this list, do the bulbs.
Textiles: things 6 to 10
One heavy curtain rather than two thin ones. A rug large enough that at least the front legs of the furniture sit on it – the most common decorating mistake is a rug that floats in the middle of the floor like a bath mat.
Add texture in layers: a woven throw, a linen cushion, something with weave you can see from across the room.

Hardware: things 11 to 14
Replace cabinet knobs and handles, and keep the originals in a labelled bag for when you move out. It takes half an hour, costs very little, and changes a kitchen more than repainting would.
Scent and sound: things 15 to 17
One scent per room rather than three competing ones. Two different candles in the same space cancel each other out and read as air freshener.

Surfaces: things 18 to 21
Clear one surface completely and leave it clear – the empty surface is what signals space. Group objects in odd numbers. And remove anything plastic from eye level, which is usually the single fastest visual upgrade in a rented kitchen.
Where to start
The bulbs, then the rug size. Those two account for most of the difference between a room that photographs well and one that never quite does.