When I had to do this, I went behind the baseboards, and when I hit doorways, I just pulled up the transition strip in the doorway and ran the wire underneath it. If you don't have any such transition strips in your doorways, you could always add a short one just to cover your speaker wire. When I got to the area below where the speaker is, I just did the fish tape thing from the speaker to a hole behind the baseboard. I had no previous fish tape experience, but there isn't all that much too it -- just persistence.