Before viewing most people look on Internet and at agents details. Ensure the agent displays good photos showing your house to best advantage, in bright light. Make them redo if unhappy. Don't overvalue, most buyers are savvy about price these days. As others have said, clean clean clean, no off putting smells, no personal stuff, store it and declutter, repaint if necessary, repair broken fittings, tidy front garden, and if dull scatter a few pots with bright plants. After viewing if you are interested, visit at different times of the day (or night), we've had some surprises in the past! If neighbours are pleasant let viewers know - if buying try and glean info about the neighbours. I agree location is usually key, but if you sell your neighbourhood's assets people may be swayed. Other than that, it's just luck 