I have rooted a lot of my strawberries from runners, and they are basically weeds, they will root quite easily. If yours have failed to root, I can think of a couple of things that may have happened..they might have dried out..you must keep them moist at all times, and placing some sort of humidity dome over the top of them(soda bottle or milk jug with the bottom cut off)will help. Another thing that may have happened is if you tried to root them in full sun..the sun will fry them..try rooting them in dappled shade, then transplanting them after they have rooted.
It would help if you told us how you tried to root your last batch, then we can maybe help you more. Donna