Oftentimes when people have problems with a recipe, it's because ingredients were measured incorrectly. That's particularly true with baking. Check out the video above for tips to help you measure more accurately.
Use liquid measuring cups (generally clear glass) for liquid ingredients, and dry measures (generally metal or plastic) for dry. Honestly, I can't stress how important this is; nothing will throw a recipe off more quickly than measuring out your flour in a liquid measuring cup (you can end up with much more than is called for in the recipe). Measuring spoons can be used for both liquid and dry ingredients.
Place the measuring cup on a flat, level surface before measuring. This goes for both liquid and dry ingredients.
Level off your dry ingredients so they're flush with the top of the measuring spoon or cup. Do this gently with a flat level, such as a ruler or the back of a knife.
Gently spoon -- don't pack -- the flour into the measuring cup. Packing will throw off a recipe by adding more flour than is called for. And don't scoop the flour using the same spoon/cup with which you're planning to measure — this will pack the flour.