Liquids:
Make sure you always are on a level surface when you measure liquids, and always use clear measuring cups. Get down at eye level to the cup while it's on your flat surface, and pour into it until you can see a level line across the desired measurement.

Using Measuring Spoons:
Always take a heaping spoonful of your ingredient on the spoon. Then take a straight object (i.e. the flat side of a knife) and level off to the lip of the spoon. All measurements using spoons are always levelled spoons.

Measuring Brown Sugars and Shortening:
Brown sugars present a different problem then dry ingredients. they must be packed into the measuring spoon to eliminate spaces that form because of it's moist nature. the same is true with shortening, and several other ingredients. Make sure you pack them full to get the right amount, and always level off to the lip of the cup.

Measuring Butter:
Instead of worrying about packing butter into a cup, check the label on the side of the stick. Often there are measurements on the side that make it easy to get the right amount. This also occurs on many lard and shortening containers.