I want to create spline in QGIS. I have tried to use Cad-tools - Create spline line\poligon but I can only draw it and can't save. What is wrong I am doing? Is there other way to create spline?
You could always try to copy and paste the created spline/polyline onto another layer and save it that way.
The plugin ArcheoCAD could also help, that is supposed to be able to join up points with curved lines.
I normally use the freehand tool to do it freehand, if you are good with a mouse then it works well. The lines end up a bit untidy when you look at them close up. In a printout at 1/10 though I have not noticed this problem