For whining, I always tell my daughter to "use her normal voice" and that usually makes her stop. I try not to give her what she wants if I notice her whining about it. For the fighting, I have heard you should let them work it out most of the time. However if they are hurting each other you need to intervene, and also if they are breaking your rules you should intervene and remind them both of the rules. To avoid jealousy, you should never take sides, regardless of whoever started it. If they can't get along then they both have to go to time out for a break. Look for opportunities to get your kids into situations that require cooperation � any activity in which they share a goal will work. They can put away their toys together, for instance, or help each other get ready for the park. And when your younger child needs help � putting on her sweater or retrieving a favorite book � your older child might be able to help instead of you.Think of noncompetitive games and other activities that will allow your children to shine as individuals while enjoying each other's company. Lots of imaginative games will let them play different yet supporting roles: setting up a pretend store, making a fort with couch pillows, having one child pretend he's an explorer while the other plays a wild animal he's befriended. When little ones get quarrelsome, a good strategy is to engross them in activities that naturally lend themselves to sharing. Finger paints and Play-Doh are too abundant and amorphous for one child to claim as his own, and you may even witness a cooperative creative endeavor, if only briefly. Be sure to praise your children lavishly any time they work things out themselves.Children tend to go through periods in which they get along well, and periods when they seem to fight all day. When your family's in one of the grumpy phases, sometimes splitting up into child/parent pairs can ease the tension. One child gets a "Mommy day" and the other a "Daddy day."