I'm currently drawing a shape based on an image on SolidWorks (2013). In this case, a household robot from SMEG
Regardless of the scale, but roughly 430 mm wide.
But I can't seem to get a clean sketch that looks like this shape (the red part of the robot. I did manage to get something that looks like it with dots stuck on a sketch image and a Spline, but it's not clean.
If this image and PDF or if you can turn it into a PDF there is a nice little software available, PDF TO DXF it should help you to have a good sketch in DXF.
The general principle is to insert the image into the sketch and then draw using the sketching tools: Spline or line and arc succession on top of the image.
I just want to say thank you for all the tips you share here. They are simple, clear and very easy to execute. And thanks to them I was finally able to improve my technique and practice easily to make my drawings on SolidWorks (2013).