If you're looking for a way to expand your outdoor space, add a porch on to the front or back of your ranch-style home. You can add a porch that stretches the entire length of the house, or you can keep it small. Center the porch around the door for a symmetrical look, or create a porch with a pathway down to a nearby driveway.
For a large expansion inside, add a second story. You can add a second story on top of your existing house, sometimes with little additional support, depending on the way your house was built. Use the extra space to make more bedrooms, add storage space or create the craft room or library you've always wanted. To add exterior and interior space, cut down on interior space and add a balcony to your second-story addition.
If you only need to expand a little, expand a single room. Turn a small kitchen into a large one, or create a dining room that serves double-duty with a space for a dining table and a breakfast nook. Make your tiny bathroom into a deluxe model, or expand your living room to create a room your friends will envy. A small, single-room expansion will typically only affect the home's exterior look slightly, so keeping the symmetry of the exterior intact isn't as big a worry as with a larger expansion.