Declutter, it never amazes me to see how in some house particulars there are pictures where there are clothes hanging about, unmade beds and stuff everywhere (French properties in particular but thats another matter). Puts me off so I expect it puts others off.
Before we put our house on the market 4 years ago (sold within 6 months despite wasting a couple of months with a time waster who put an offer in so took house off market and then estate agent told us he had put an offer in elsewhere (we were just a back up plan I think) we did the following:
we redecorated, inside and out (tart up really), decluttered, removed evidence of pets etc when people came to view (no one wants to see a litter tray or smelly dog bed - we had a garden storage chest outside that we plonked them in whilst people were viewing), put fresh flowers in the hallway, made sure beds were made before viewers turned up, tv/radio turned off etc.
Also what we did when we moved out was leave a little pack with details where the stop cock was, of bus/train times, taxis, takeaways, doctors etc