All that Summer mud and guests tramping through the house builds up quicker than you realise, even if you vacuum the floors every week. Maybe that carpet is still cream under all that embedded pet hair, dust, and the tub of glitter that accidentally got spilled after a festival? A deep clean is the easiest way to make your rooms look bigger and brighter (and you can always pay someone to do it if you can't be bothered yourself). Give your sofa cushions and throws a bit of a spruce too - you're going to be spending a lot of time with them over the coming months.