Nice curves
If you look at professionally designed components you will often see smooth curves.
Parts with smooth curves are good for DFM (design for
manufacturing) and look good. You can easily create parts with smooth curves. For example, we might want to go from:

To make smooth shapes around holes and cutouts:
- Delete the outer shape (e.g. the large rectangle above).
- For each hole or cutout do Line | Contour | Outside.
- Choose Edit | Select All.
- Choose Line | Intersect.
- Delete unwanted segments.
- Where needed: select two arcs from the contours and choose Line | Tangents.
- Choose Edit | Select All.
- Choose Line | Intersect.
- Delete unwanted segments.
- For any two lines meeting at a sharp angle, select them and apply Line | Corner | Round.