Mirrors increase light
Mirrors opposite windows in dark spaces will increase the available light I always use this device - it banishes dark corners

Comfy Beds
No matter how ropey your bed, a mattress topper will make it more comfortable. I have one on every bed in the house. I bought the most basic bed for the guest room and everyone who sleeps there says they had the best night's sleep. We use them summer and winter alike.

Curtain Rails
If your curtain rings are sticking on the rail, rub the rail with candle wax. This will help the rings slide. Rub the top of the rail where the rings meet with candle wax.

Colourful Kitchen
I have to have a bright colour in the kitchen. The kitchen is the first place you see in the morning and if it's a cheerful colour you start the day with a smile.