I love strawberry plants! My favorite part about them is when you buy your first plants, you never really have to buy more unless you want new varieties, because the runners of strawberries will root themselves just about anywhere. I have been able to use that to my advantage every time I have built a new garden.
My trick is this little hook. It is just a piece of 14 gauge wire that I cut into a 2 1/2 inch section and I bent to this shape. I use it as a staple to put the runner plant into the ground where I want it. When it starts to root I just cut off the runner from the mother plant and I have a whole new strawberry plant, ready to fill in any blank spaces I may have.
If you don't want your plants where the runners can reach, you can also place a small pot and staple the runner into dirt in that... when it roots, just cut it off the mother plant and transplant the pot wherever you want new strawberry plants!