For those of you advocating fabric softeners or dryer sheets...
These products DO NOT soften fabrics, that is actually impossible. What they do is add silicone to the fibers which make them "feel" softer to you but since your car has no nerve endings why bother?
Adding silicone to the fibers reduces absorbency in natural fibers and restricts adsorbency in man made fibers. Silicone also reduces a fabric's ability to remove excess wax and polish and it's ability to buff. In addition the silicone can be transferred to the vehicle's surface, especially on hot surfaces.
Simply don't ever use softeners of any form.