Just learn a few basic pieces, and you can make them in different fabrics and sizes. Great seamstresses can pull apart adult garments and reuse the fabric for children's clothes. Special Occasion Dresses can be hard to find, and a good thing to make. You will have to baste it together, and then rip it apart, using the altered muslin pieces are your pattern. Sewing for your home can result in significant savings and beautiful, unique decor.
Window treatments are so casual now.
Sometimes people just drape the fabric, and don't even sew it. You can make tablecloths, pillows, bedspreads- anything out of fabric. Cloth napkins are easy to make, and with placemats make great gifts. I like to make dolls also. Some people have no choice but to sew, as they are hard to fit.