Head Clipping help in regards to the heifers attitude

I have a show starting and Wednesday and decided to clip the heifer today since there was little to be done. However she decided to go berserk and after two hours of just trying to do her head I decided to let her go before we try and kill each other. Is there any actions I could take to minimize the issue as I finish her tomorrow ?

Put her in a squeeze and crank her head down.i don't clip any heads in a clipping chute(they are not sturdy enough if they decide to freak out)

Try turning the clippers on, and putting the clippers up against her head ( blades away from her) for about 3-5 minutes to let her get use to the noise and vibrations. May be a lil to late for this to help but may come in handy on the next one. Good luck

Blind fold her and stuff her ears full of paper towels.

I agree with ROMAX.  I clip hundreds of heads per year.  Put her in a squeeze chute.  Use a halter to snub her head to the side, clip as much as you can, then reverse to the other side.  You might have to touch up a couple of spots with the halter off to finish.  Believe me if you clip enough mature Angus cows, you'll get very good at this!

I'd be cautious of the blindfold method. I've seen it work but I've also seen a couple of complete wrecks when they cover the heifer's eyes.  It really depends on the animal.

Get a medium blade for your 2 speed clippers.  They are quiet and sometimes it makes it easier.

Adding to the important information given in the above posts; for newbies, try to clip the head while the clipper head is still cool. Find an area that the animal is comfortable to have clipped and keep expanding that area.  You may have to go back to the neck and expand the area forward over the jaw with long strokes.  Often the nose is the final challenge, so don't start there.  I have never had to leave a head partly clipped while custom fitting.
I believe its a good practice to skin show animals in early spring.  This gives them a positive clipping experience on their entire body when they are itching to get rid of old hair.  The clippers provide a body massage vs. blocking must feel like a pest summer fly to the animal.  BTW, I have one Angus cow that I've spring skinned entirely without halter or chute, just stands beside the cow I was working on. This shows you the memory they have and how they will (or not) trust you.