As you are probably aware, self-rising flour is just flour with a leavening agent added to it. Self-rising flour has baking powder added to it and sometimes salt. The advantage of self-rising flour is that the baking powder is mixed in uniformly. Its use is limited because different recipes call for different proportions of flour to baking powder and the baking powder will lose its effectiveness over time. The quality of baked items using this flour can fluctuate. It is best to only use self-rising flour in those recipes that specifically call for it.
If from time to time you find yourself baking and not having the correct type of flour called for in the recipe, there are simple solutions. It is always best when possible to use the specific flour the recipe calls for. Here are some substitutions I found on www.joyofbaking.com:
For 1-cup all-purpose flour you can substitute 1-cup + 2-tablespoons sifted cake flour.
For 1-cup bread flour you can substitute 1-cup all-purpose flour and work the dough longer to develop the proper amount of gluten.
For 1-cup cake flour you can substitute 3/4-cup all-purpose flour and 2-tablespoons cornstarch.
For 2-cups pastry flour you can substitute 1-1/3-cup all purpose flour and 2/3-cup cake flour.
For self-rising flour you can substitute 1 cup similar grade all-purpose flour and 1-1/2-teaspoon baking powder and 1/4-teaspoon salt.
Now go bake something!