These tips from John Barricelli, owner of SoNo Baking Company and Cafe and host of "Everyday Baking from Everyday Food," will help you with all the baking basics, from measuring flour to testing your cake for doneness.
Measure liquids in a clear measuring cup (shown here), which allows you to read measurements at eye level. Measure dry and semi-solid ingredients in graduated dry measuring cups -- they allow you to level ingredients with a straight edge.
Sift flour and other dry ingredients only when called for specifically in the recipe. Use the dip-and-sweep method (dip your measuring cup into the flour, and then sweep a knife across the top of the cup) to ensure you've measured the proper amount.
To test for doneness, use a toothpick or wooden skewer inserted into the center of the cake -- it should come out clean. The cake should spring back when lightly touched, and should be just pulling away from the sides of the pan.
When prepping a cake pan or muffin tin, a pastry brush can help with the hard-to-reach spots. Brushing the surface between cups will prevent muffin tops from sticking to the pan. Use softened butter rather than melted butter.