Sweeps using profile families from copies linework

This post originates in a reply from Alfredo Medina  to one of my Revit Discussion group posts. The issue is about trying to make up profiles to sweep in families (particularly windows by copying and pasting into a profile family. It rarely works but Alfredo's workaround is this:

Copy the lines from the profile family, and paste them into the sketch of a new extrusion in a model family. Try to finish the extrusion. If the extrusion does not work, Revit will tell you what the problem is (overlapping lines, bad connections, etc...), and that will help you to fix the sketch. If you finish the extrusion, and it works, or if it works after correcting the issues, then edit the extrusion, so that you have acccess to the fixed sketch again. Copy that sketch, and paste it in the profile family, replacing the old one. Then load the fixed profile into the other family where you wanted to use the profile in a sweep. Now the sweep will work.