Flips
Sometimes singers want to achieve a sudden lightening of tone. Country singers do it ... see Ellen Peterson in this great clip, Swiss mountain goatherds do it too, but it also appears elsewhere... Whitney Houston ('Run to You') and Mariah Carey and Thom Yorke of Radiohead ('Creep') all use it. And Sam Smith, Birdy and many more..
What it is: A sudden shutting down of chest voice non a rising pitch. It is commonly used in context of a vowel change, most often from a larger to a smaller vowel. Commonly |O| to |U| or in classic Swiss style |e| to |i| as in 'yodelehee'. Allow the larynx to quickly rise, helping it by lifting the back of the tongue and the jaw slightly, just as you make the vowel change.
Reverse Flip:
Harder to execute than an upward flip. Listen to Freddy Mercury on Bohemial Rhapsody 'Leave it all behind and face the truth' Or in fact Creep again, when Thom Yourke drops down from a heady tone iwith a sudden shift to chest dominated voice on the line 'she runs ' in the midsection.
Growls and Roughs
Resonance overloading.