If you need layers your sketch is too complicated. make another sketch with another feature. Pro/Engineer used to propagate the 7-7-7 rule (thanks freecad-heini-1 for bringing to our attention) which says a sketch should
- have no more than 7 elements
- have no more than 7 dimensions
- take no longer than 7 minutes.
It is widely agreed in the FreeCAD community that nowadays these numbers can be raised, but the idea of simple sketches is worth some more thoughts.