Create a new document in your CAD or vector illustration program (ex: AutoCAD, Rhinoceros 3D, Adobe Illustrator or Inskcape) measuring 610 mm (h) x 1220 mm (w) at 72 dpi.
If you use Adobe Illustrator (recommended) there are numerous tutorials available to help with the following instructions. And you can use this template to quickly set up your files.
Layout your vector design. The entire design must fit within the artboard. Keep your design within the magenta bounding lines in the template to avoid hitting the limit switches during a run.
Eliminate any duplicate paths. (Easy to do with "SelDup" command in Rhinoceros).
Join all contiguous paths. For example, a square should be a single path not 4 individual sides.
Set all line widths to 0.1 pt.
Eliminate all fills.
Use different colors for paths that will be cut at different speed/power settings or separate runs (bounding box after infill, for example).
Save in SVG 1.2 Tiny format.