A few years ago I started making my own Dho-gazza nets. I looked around on the internet for years trying to find information but it was very scarce. And it's really something that you need to see to fully understand.
I finally learned how from my friend Jimmy Walker on one of his visits to Florida. Once I saw it done it was just a matter of practice. I've tried to explain it to a few people but I think this video series will make it much easier. It's not the most professional video but I hope it helps (just ignore the barking dog & screaming parrot).
If you want to make your own nets I recommend starting with the net making kit from Jann's Netcraft http://www.jannsnetcraft.com/