Fresh flowers throughout; classical music in the background; freshly baked cookies (you can buy the ready to bake ones) will make your house smell wonderful and be most welcoming.
This is the time to buy rich bedroom duvets with textured accent pillows and new bathroom towels. Rich scented soaps add another special touch.
Open the curtains; let the sun shine in. Put all the lights on! Remove all the clutter. Less is more in many cases because it will make the space feel bigger.