In perspective drawing, designers express 3D shapes by drawing auxiliary lines that construct surfaces and drawing design curves on them. However, drawing auxiliary lines can be challenging, and too many of them can make the drawing difficult to understand. To address these issues, we present a novel 3D sketching system that allows the user to quickly and easily create instant auxiliary lines and instant sketch surfaces for drawing desired 3D curves with fluent bimanual touch and pen interactions. We produced a concept sketch using our system to showcase its potential usefulness.