http://www.canismajor.com/dog/alpha1.html#Exercises
That link has a few good techniques. It's difficult for me to explain ... I hope none of this comes out wrong ... but there are a few different ways I have worked with Mogli over the years. He has never injured himself or cried in pain, nor did I feel that I was being overly physical.
Mogli doesn't get in trouble very often. More than anything when he does it's just him being a showoff anyways.
... I have picked him up by his loose neck skin from day 1. So at almost 7, he does not mind and is totally comfortable being picked up and handled that way. That being said, if he's acting up, I might secure him by the loose skin, then lay him on his side, while holding his skin like a handle so he does not move. This is the best way since holding him like that asserts me complete physical control.
You can him on his back, and hold gently but firmly over the neck. Don't GRIP the neck, but almost like a handcuff around, hand shaped like holding a cup ... so fingers touching the ground like a C ... while blocking his side or with a hand on the chest or belly to prevent squirming.
You could gently but firmly hold his snout closed while forcing eye contact.
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The biggest thing with any training is to be consistent. Use the same tone and words, combined with hand signals to convey your messages. The problem is you have to extablish this physical component before they really grasp the meaning in this case.
These days with Mogli I snap ... hold up my index finger ... place it in front of my face and say "look at me" or ... "enough" ...