If your house is average, that doesn't mean that you must settle for an average price. Some houses sell for more than their seemingly similar competition. The real estate market is cyclical from year to year and even from season to season. Its down periods are almost always followed by ups. Also, some seasons are better for sellers.
Spring is usually active while major holiday periods are quiet.
The pattern will vary from place to place. A real estate agent can tell you when buyers are most active in your area. There is one exception to the rule to avoid flat periods. You can turn a flat market to your advantage if you want to sell a cheap house so you can move up to a more expensive one. That's because you can save more money on the new house than you will lose on the old one.