I use a style curve and a 2"x18" clear ruler with 1/16th" markings for pattern making along with a metal yardstick and a tape measure.  My daughter doesn't use any curved rulers.  She free hand draws her curves.  I have friends who variously use french curves, hip curves, flexable rulers, and style curves.  I think it all comes down to personal preference and experience.  Most of the tools can be gotten at the fabric store or hardware store.  My t-square, L-square, and metal yardstick are all building/engineering tools, not pattern making tools.  My style curve, clear ruler, and tape measure come from my local fabric/quilting stores.

Chris