This video has an excellent tutorial. https://www.youtube.com/watch?v=bM5qvXJjifA
You might try this post as well, Jolene! Hope it helps! http://www.aconcordcarpenter.com/using-cable-hang-string-lights.html
Here are some details. I also hung ours under a second-story deck without using wire, and they have been fine. Having the deck helps to protect them.
Jolene..Jolene..Jolene..Jolene...When you buy the light they usually have the clips and hook on the gutter. Love your name and so does Dolly!
Not all light strings come with built in clips or hooks.