I do the same things already suggested mainly--lots of treats, slow exposure to the clippers. I also generally do one nail at a time. Fortunately, most of my dogs dig so much they don't need their nails trimmed.

My worst nail trimmer is Chum. He can't stand having his paws touched at all. He gets growly, snarly and just plain miserable about it. I've working slowly on getting him to let me just play with his paws. I've found covering one hand in peanut butter and petting with the other works wonders!! It's disgusting but it works!