As others have pointed out, it's tough. Sometimes you have to deal with the psychological issue that's causing your resistance to the action. As physically easy as it may be to pick up the phone and call your sister, there may be all sorts of other factors making that action unpleasant.
I'll sometimes break the task down even further. In the "organizing CDs" example, I might change the Next Action to "Pull out first CD." I've even created NAs like "Look at CD collection." That'll at least get me thinking about what I need to do, and can get me started.