The very best advice I can give any seller is to put your best foot forward, make sure that your property shows the best possible, in short, people will overlook being dated if everything is clean and well maintained. Properties do not have to be new to be nice, but no one wants to clean up after someone else so I stress CLEAN, CLEAN, CLEAN and keep it that way throughout your marketing period! Box up everything you can live without and de-clutter so people will see the property and not be distracted by 'stuff'.
It is also immperative to select an agent you can communicate with, one that knows the market and has experience or access to a support staff and teams of agents and brokers that can assist them in assisting you. Find out what kind of marketing your agent/agency are going to provide you and make sure you are getting the guidance and service to make your move a success.