the only limit will be your imagination,
when you see a bit of second hand furniture you have to look past what it is and imagine what it could be.
dead comfy sofa but yukky pattern.....throws were designed for these
not so attractive but clean lines table....get the paint out
yukky flooring, chuck out nasty carpet put down interlocking floorboards (quite often works out cheaper than fitted carpet.
bad lighting...plain mirrors to send the light round and make the place seem bigger.
nice big pot plant display in corner, light in the base behind the leaves(not hot or you'll have a fire or dead plant)...light feature