shaping bird's nest gourds
Probably I was the last person to discover this technique but on the off chance I'm not...I'll post it.
You can shape bird's nest gourds and add decorative or interesting features by taking a young gourd and wrapping it with different materials. Gorilla duct-tape is very strong and doesn't seem affected by rain. You can take say a 1" strip of it and wrap the gourd's circumference. The gourd will continue growing except where the tape was...or wire or whatever you chose to use. I like multiple circles on the gourds...they bulge out above and below the restriction you put on them.