Fortunately, it happens that strawberries are ready to be thinned well after I have completed all other garden activities. After cooler weather and maybe a few light frosts to harden the newest plants I thin the plants to about six per square foot.
I thin the least hardy of the plants from runners and remove the runners. Then I cover them with a straw mulch. The past two years we've had extended periods of below freezing temperatures with lows approaching 10 degrees, so I believe the precaution is appropriate.
First I took out all the plants that were in the area of the ever-bearing strawberries. This was originally about half the bed. I found a couple of other gardeners who were interested in planting them.
I wasn't pleased with the size and performance of the "ever-bearing" strawberries so I weeded them out as best I could and transplanted runners from the June-bearing plants. We'll see next August how effective I was in choosing.
Before the really cold weather (low twenties and below, if I'm lucky) I took some of my rye straw, of which I have plenty at least this year, and covered the strawberry bed with at least four inches. And I forgot about the strawberry plants until spring, when I removed the straw to reveal plants that are ready to put out more runners and more fruit.
Read more: Strawberry Plant Care for Winter at Garden Guides.