Declutter, declutter, declutter. Throw the stuff into the attic if you have to but declutter. I'm speaking both as a buyer and a seller at the moment. We put a couple of hours work into our house before every viewing, cleaning, tidying, throwing stuff out, even moving it temporarily into the car if we have to! And, thankfully, the viewings are brisk and we're even getting a couple of offers. You'll always get an experienced head who can see past the decor, clutter etc etc but IMHO FTBs and anyone who wants a handy enough move (people with kids, busy lives etc) will take the most attractive house on the block. Lots of people out there these days are also underbidding to try and get a bargain and a dingy house won't help!!