If you can't draw well, or precisely, perhaps you can trace images from a phone App using Augmented Reality. Clever idea for the right kind of application. Warns that this is best done with the aid of a tripod. Available on IOS for now, Right now it only works with A4 size paper, but they report that it will ultimately be linked to the Project Tango system to detect location, on a Lenovo Phone, with the potential of doing full size murals.
In ITunes: " ... SketchAR is an application through which the user sees a virtual image on the surface of which they are planning to trace a sketch. In one hand, the user holds a phone and sees a virtual image, while the other hand traces virtual lines already on the paper ... "
SketchAR puts virtual images on paper to let you trace drawings from your phone by Dami Lee @dami_lee In TheVerge: ..