I start with a good tap to the top of the head or the back. Depending on your speed and flexibility the back could be the easiest target. This simulates another chicken saying "hey, buzz off, I outrank you". They can take a pretty firm tap- one or two fingers, like a hen pecking a lower member of the flock.
Obviously you don't want to go for bodily harm. However, it should (after a little practice) be something that she doesn't want to have happen again, i.e. it's not a game where she then escalates and starts jumping at you, or tries to return the peck.
If she challenges you further-- that's when I personally go for the pin down. Keeping her pinned (and do watch her breathing- make sure you're not constricting her lungs/air sacs!!) until she stops struggling. By the end of the pin down, she should have her head down (away from you) with a surrender mentality. If you get the defiant gaze/attempt to peck you, (you'll know it if you see it), use your other hand to give her a light peck to the top of head (one finger like a beak). If she doesn't lower it then, use one or two fingers to gently push her head down, like an inch off the ground-- continue to do this until she holds her own head down and isn't trying to get up.
The goal is for her to never consider charging, pecking or otherwise being nasty to you ever again.
If she's a real .... piece of work ...my last step is to put them on their side/back similar to the pin down, except she doesn't have her feet under her- hold down (being very careful not to restrict breathing)
while she struggles, probably kicking her feet etc.- wait til she stops- and stays put as you release the pressure.
Others have noted that after some practice with both the pecking and pin-down, that they got the best results on a fresh entry (i.e. you going into your backyard for the first time of the day, or whenever she's at her worst) -- and went straight for the pin down.
