I use kind of a backyard/oldschool method I guess.
With the plugs in the wire caps, i just connect jumper cables. Each cable end holds 2 plugs perfect, then ground them to the frame/engine/whatever I can find.
Then, when I'm cranking, i know they have a good ground cause I can see them all sparking away.
This is a good setup for quick diagnostics, turning the ignition off/on.
If your a newbie who might forget the ignition on, or take long time to think/examine things etc. i would deffinately consider just removing the power wires to the coils (as mentioned), and be done with the whole possibility of damage/failure.
Cheers.