All grey interiors.
Large flower patterned wallpaper in bedrooms, especially in shades of purple, teal or burgundy.
Bouclé upholstered chairs, stools and sofas.
Sheepskins or faux sheepskins over the back of dining chairs. All I can think of is digging out the crumbs and food particles like Mr Twit's beard.
Reed diffusers.
"Eat. Bathe. Fuck" signs on walls.
"Mortuary slab" free-standing kitchen worktop units with tall stools down one side that anyone under 5' 2" will struggle to clamber onto.
A random area of bare brick or stonework left unplastered in an old house or a former industrial building converted to apartments where the rest of the wall has been plastered.
Pseudo fireplaces in living rooms filled with sawn logs.
Knocking two rooms into one larger room but leaving the chimney breast wall and fireplace or woodburning stove in situ (ie with no walls either side of the chimney breast).
Open plan kitchen, dining, living areas in small houses (a number of developers are now building houses like this which obscures just how small the ground floor room areas would be had they been designed as individual rooms with doors).