How do I pinch back dahlias for better bloom?

Question:I know one is supposed to "pinch back" dahlias, but I don't know how this is done! Thanks!

Answers:
you pinch back dahlias for two reasons one, to promote lots of growth and numerous blooms, two to increase the size of the blooms, in the first case you pinch out the growing tips when the plant is about a foot high, to increase the size of the blooms pinch out two of the buds at the end of each stem as soon as they start to show