The best microwave tip I know is, learn about the "cold spots" in your microwave so you don't end up with unevenly cooked chicken. To learn your microwave's "cold spots," line the bottom of your microwave oven with wax paper and then spread an eighth-inch layer of pancake batter over it. Turn the oven on HIGH, and then check it at 30 second intervals. At some point, (in my case after a minute and a half), you'll see that in some places the batter is dried out and hard, while in others, it's still soupy, as if the heat hadn't touched it. Once I made this check, I gained an immense respect for the fact that microwaves don't necessarily cook evenly, and I've made sure to compensate ever since by stirring or turning foods as directed in microwave recipes.
Do not use utensils with metal trim (including the gold trim on fine china), handle clamps, or fastening screws. Metal trim can cause arcing (sparking). Aluminum foil, in small amounts on the other hand, won't cause arcing in most microwaves as long as it doesn't touch the sides of the oven.
The coverings used in microwave cooking have definite purposes: use plastic wrap to steam and tenderize; use wax paper to hold in heat without steaming; use paper towels to absorb moisture, yet hold in heat.
To obtain a crisp, crunchy crumb-coated chicken, first cook covered with wax paper, then switch to a paper towel covering and, finally, complete cooking with chicken uncovered.
If the bony parts of your chicken are overcooking before the meatier parts are done, shield the bony parts by placing strips of thin aluminum foil over them.
If you're microwaving chicken livers, prick each one to allow steam to escape. Before I knew this tip, I've had them explode in the oven.
Microwave recipes usually call for smaller amounts of seasonings than conventionally cooked dishes. Microwaving tends to intensify flavors, so you won't need as much seasoning.
Don't ignore the standing time called for in some of these recipes. In microwave cookery, standing time allows further cooking to occur after you have removed the food from the microwave oven. Covering the food holds heat in and speeds this final, important step. When I've cheated on this step, I've found the chicken hard to carve and undercooked.
When possible, arrange food in a circular or donut shape; without corners, food cooks more evenly from all sides. For example, if you're cooking drumsticks, arrange them like a wagon wheel with the meatier portions at the outer edge, and the drum stick end in the center.
Thin foods cook faster than thick foods because microwaves lose power after they penetrate food.
Ingredients also affect cooking time. Foods higher in sugar or fat heat faster and to higher temperatures than do those with lower sugar or fat content.
When the recipe says "70% power," or MEDIUM HIGH, don't be tempted to get things done faster by going for 100% power. At 70% power, the microwaves cook the product more slowly but also more evenly, so there's less worry about cold spots.
From the Perdue Chicken Cookbook