Additions and Substitutions
Quick bread recipes are fairly versatile -- you can add and substitute ingredients with greater freedom than you can with most other baked goods. To lower the fat, you can substitute some of the oil with an equal amount of almost any fruit puree (applesauce, baby food prunes, pumpkin puree, mashed bananas). You can add nuts and dried fruits to your heart's content, and substitute one kind of nut, dried fruit or fresh fruit for another. 

When you use dried fruit in a quick bread recipe, try soaking the fruit first. Not only will this make the fruit moist and tender, but adding moisture to the fruit before you put it into the batter will also preserve the moisture of the bread because the fruit will soak up less moisture from the batter while it bakes. Place the dried fruit in a heatproof bowl and pour just enough boiling water over it to cover it up. Let it soak for 15 minutes or so, then drain and add to the finished batter. If you want to get fancy, you can even soak the fruit in hot apple or orange juice. Or, soak the fruit overnight in whiskey or rum to add a twist of sophistication. Don't sprinkle dried fruit on top of the quick bread before baking - it will get dried out and burnt, and won't make a very attractive or tasty topper. 

Add a finishing touch and a burst of flavor to finished quick breads by glazing them! Allow them to cool somewhat, and then make a simple mixture of confectioners' sugar and a little milk or fruit juice. Some especially popular choices are orange and lemon juice, for the fragrant, tart zing they add. 

The Magic is in the Mixing
The real secret to perfectly moist, tender and well-shaped quick bread is to be scrupulously careful in your mixing. Combine the dry ingredients - flour, leavener, salt and spices - in one bowl and mix them thoroughly with a wire whisk. In another bowl, beat together the fat, sugar and eggs in the order the recipe advises. Stir any other ingredients - fruit or fruit puree, nuts, flavorings - into the wet ingredients. Only when each bowl of ingredients is mixed thoroughly should they be combined. When you are ready, pour the dry ingredients into the wet ones and fold them together gently. Do this part by hand rather than with a mixer so you can use a gentle touch. Only stir until all the dry ingredients are moistened. Don't worry about a few lumps-they will disappear during baking. 

Troubleshooting
There are a few common problems that people encounter when baking quick breads. Luckily, most of these problems are completely avoidable once you understand what causes them: 

Bread sticks to pan
There are a few reasons why the bread may stick to the pan. Unless you're using high-quality nonstick metal or silicone baking pans, you should always grease the pans before you pour in the batter. The best thing to use for greasing the pan is shortening, because its melting point is higher than any other kind of fat, and therefore maintains a "shield" between the pan and the batter while the bread is baking. If you use a liquid form of fat such as vegetable oil, it will simply get absorbed into the batter. People also experience sticking problems when they use a bread recipe that is especially low in fat. Usually, the fat in the bread itself helps to prevent sticking, and when there isn't very much fat, the bread is more likely to become stuck to the pan. The best solution to this problem is to use a more generous amount of shortening to grease the pan, or buy some really good nonstick pans. You can also prevent sticking by removing the bread from the pan within a few minutes of taking it out of the oven. 

There are big holes and 'tunnels' in the bread, and/or the bread is tough
These problems are usually caused by overmixing. See the paragraph above about mixing technique. 

There's a big crack down the middle of the quick bread loaf
The crack on top happens when top of the loaf 'sets' in the heat of the oven before the bread is finished rising. It's normal for there to be a crack down the middle of most quick bread loaves. Don't worry about it. 

The bread looks done on the outside but it's still raw in the middle
This is one of the most common quick bread problems, and it can be caused by a few different factors. The oven temperature could be too high. Most ovens are not accurate: they usually vary anywhere from 25 to 75 degrees F between the number you see on the dial and the actual temperature of the oven. The best way to get an accurate temperature us to use an oven thermometer than is made to hang from the oven rack. 
If the outside of the bread is done before the middle, try lowering the oven temperature and/or putting a loose tent of foil over the top of the bread so it won't burn before the middle has time to catch up. Another cause of the 'raw center' problem is using a different size pan that the recipe calls for. One of the nice things about quick breads is that you can use the same batter to make muffins, mini loaves, jumbo loaves, or just about any shape at all. But, each size requires slightly different baking times, and sometimes, different baking temperatures, too. The larger and thicker the loaf, the longer it's going to take to bake. If you're using a different size pan than your recipe calls for, adjust the baking time accordingly and check the bread often. 
 

Bread Baking Basics