Even for kids, writing in a journal is a great way to express and process one's feelings. In fact, you may want to introduce the concept of journaling by getting one for yourself, and letting your kids see you taking some time each day to write out your thoughts and feelings.
If you're bothered by the thought of what your child might write, consider pairing up for a dual-author journal. Pick up a blank spiral notebook and take turns writing entries/notes back and forth to each other. Especially for kids who worry about hurting a parent's feelings, addressing their "big ticket" questions and concerns in this manner breaks the ice and makes it easier to eventually become comfortable sharing them face to face.
Drafting letters--with the intention of mailing them or not--is another effective tool for helping kids process their feelings. It's a strategy that can be especially helpful for kids who have little or no contact with the recipient. Putting their true thoughts down on paper in this manner gives them a tangible way of dealing with their emotions, so that they don't get bottled up and ignored, only to resurface later.
Keep in mind, too, that even young children can create photo journals and letters, or they can say their thoughts out loud and have an adult write them down.
If your children are angry over a divorce or loss, consider seeking out a kids' support group through DivorceCare or a local community mental health organization. Many organizations offer a combination of programs for adults and kids, so that parents can help their children through the grief process and develop healthy strategies for moving forward.
Make sure that your children are also getting plenty of exercise. If this is a struggle, consider walking or jogging together several times a week. This will give you a chance to bond while also allowing each of you the opportunity to sort through your emotions while engaging in a physical activity--which can also help you sleep better at night, equip you for handling stress more effectively, and give you more energy for getting through the day.
Blowing Off Steam
Finally, teach your children some specific and acceptable strategies for blowing of steam, such as: yelling into a pillow, sprinting up the street or around your house, using a punching bag, or systematically tensing and releasing his or her muscles--starting with the toes and moving all the way up to the forehead. These strategies may seem simplistic, but it's important not to take for granted that your kids' anger will resolve on its own. Youngsters have to be taught how to effectively relieve themselves of the overwhelming tension and anger they feel.