not sure this helps. i trace by
1) scan item or take picture of it
2) in Autocad or other cad program import image
3) if image is black lines on white background draw red lines on a separate layer over the image lines. it helps to draw a red line a certain length and adjust image scale until it's length matches the red line.
4) when everything has been traced usually using regular computer mouse with red lines then either hide or delete the imported image
5) the red lines on the separate layer can have their color changed, they were only red to tell the difference between traced lines and the imported images lines
.....some people really like a Wacom pen type input device especially if you are used to drawing on paper.
.....my department does not believe in spending money for equipment unless there is no other way and so far tracing a scanned drawing seems to work ok.