I've bought and sold many times over the years and I've always followed the kind of advice provided here, especially re. keeping your house clean, tidy and fresh smelling.
Ultimately though, the top three priorities for me have been location, price, good neighbours.
By way of illustration....
We once viewed two houses in the same location, one we had done our homework on and liked.
The couple who owned the first house had followed all the usual advice to the letter: their house was spotless, crisp white bedding, freshly painted throughout, soft lighting, flowers in every room, the smell of freshly brewed coffee, very little in the way of personal stuff like photos, garden immaculate. When asked about their own plans, they weren't forthcoming. Nor did they offer any information about local amenities etc. As we took our leave, we spotted the next door neighbour at her window but she darted back when she realized that she'd been seen.
The second owners were a couple with three young children, dog, cat, guinea pigs. Fairly chaotic and untidy, with general clutter everywhere: children's art work, family photos etc. The back garden full of children playing: toys, swing, trampoline etc. - all supervised by a neighbour, who greeted us with a smile and chatted away with advice and information about schools etc.
The two houses were identical in terms of overall size, layout, rooms etc. The second was on the market for £25,000 less than the first and, like us, the couple wanted to move during the school holidays.
We bought the second house. We never regretted it