TONE

The tone is the defining point of an individual's "playing
personality". What is generally considered to be a
good tone is clear, dark, and rich in "color". "Bright"
sounds are shrill annoying and generally unwelcomed by
the non-flautists sitting around you in orchestra or band.
The key to good tone is breath support and
embouchure setting.

Follow the diagrams for a better look...

This picture taken from The
Gilbert Legacy shows the
correct embouchure, not too
tight, and not in the common
"smile" form. This
embouchure makes playing
fast passages with a good tone
quite easy.

This picture shows the incorrect "smile"
embouchure. This embouchure isn't as flexible,
making passages that skip between octaves quickly
rather difficult to play. It will also produce either a
harsh or airy tone, depending on other variables
such as breath support (there are those words
again!) and air speed.