what would be the prefered method

I always had success rooting them in damp soil. Take a cutting with a few leaves and pinch off the leaves. it will root where the leaves were pinched off. Put them somewhere out of the sun until they have their roots.
If you don't like the smell of the flowers you can just cut them off.

Haven't grown that in many years, but I always just rooted them in water....

One of our other members suggested using a Forsythe pot for rooting cuttings. There's a very nice step-by-step set of instructions, with a bit of information on specific plants, here:
http://www.extension.umn.edu/d...
I've been meaning to try it, but haven't gotten to it just yet.