Are you talking about annual or perennial fuchsias? If they are annual, just take a non-flowering shoot, cut just below a node (joint) and remove lower leaves. Pop into a glass of water, and you will see roots forming in a week or two. Once there are plenty of roots, pot up in compost - et voila!

they say rain water is best

Just a word of warning - I've always found fuchsia cuttings taken this late in the season don't survive the winter. I now take cuttings early in the season instead.