There are different ways to sell your property and there is not one perfect way to do it. Options are selling with a set price, auction, negotiation or tender.
Best ways vary and depend on what type of apartment you have. For example Auction is not as successful in the Apartment Market as it is in the housing market.
So there is not one answer as different apartments require different methods. This is where working with your agent and figuring out what method best suits you is required.
You can do this by asking your agent the last three sales in your building and what method was used. This will give you a good idea to what approach is best suited to your type of apartment. Ie which sales methods achieved the highest prices.