Designate the first hour after kids get home from school as homework time. Do not allow them to talk on the phone, watch TV, play outside or any other type activity that might be construed as leisure or better than homework. Make it an unspoken rule, so there are no hard feelings or attempts to combat the rule. If they don't have homework they can read a book, do constructive Internet activities conducive to learning, or write in their journals. This keeps them from being tempted to lie about having homework in order to play or talk on the phone, etc.