What is the most effective way to make these strings?

[JIaCTuK (Dave)]

I tried to use curves but it wasn’t accurate and the ends were very sharp

[oo_1942 (Kim)]

Create a shape with a mesh and delete it, leaving only the edges. (For round shapes, use bevel.
Convert the remaining edges to curves to give them thickness.

[DNorman]

Or just use a 3d curve and a couple of mesh spheres to cap the ends (or a more fancy cap mesh)

(I placed the caps manually, you could do it with Geometry nodes but that might be overkill for this)

[JIaCTuK (Dave)]

Thank you so much☺️

[JIaCTuK (Dave)]

Also a solution