The double spey cast is beautiful. I had a hard time getting this cast under control. As simple as it is, I found it to be much more difficult than touch and go casts such as the snake roll. Now I am no "expert" spey caster but I am driven! It took me a full two weeks of focusing on the cast and these are mistakes I encountered along the way.

Equipment used for practice:
Orvis Clearwater 11ft 8wt Switch Rod
Echo Bravo Saltwater Reel 7-9wt
40lb Berkley Trilene Big Game (running line)
480 Grain Sceintific Anglers Floating Skagit Head
Rio IMOW Tips Medium 10ft Intermediate
2" Marabou Intruder Fly