Take away the comforts of their bedroom and give lots of chores.  If that doesn't work, get out with your child.  Yes, he/she will just about kick and scream at first, but, if he/she doesn't appear to have friends or activities, then it falls upon the parent to be the friend and create an activity.  I was told, "Do something or I'll find something for you to do," and I found something to do quickly, because, my mom backed it up with things I genuinely did not want to do.  Be creative, don't make threats, and back every promise up with affirmative actiion.  Yes, I do have children, and I do have to practice these same tactics.  I have 4 children and have to treat each one individually as no two people are exactly alike!  But, its amazing how many similarities they have. I can clear my house in thirty seconds with one word...chores!