Its rules are simple. Insert as many French words as you know into the sentence, fill in the rest with English, then speak it with absolute conviction.
A man is accused of driving his car "avec toute la finesse d'un Rangers fan" (Miles Kington)
A door-to-door seller assures his customers "je ne suis pas un nutter religieux" (Miles Kington)
"Je suis un rock star." (Bill Wyman)
A famous defendant who "ject un brickbat a le dit Justice, que narrowly mist". (Old English court case)
“Le maker de 'franglais' est le dead.” (Fark)
Kington wrote several books about Franglais. Link -via Fark, where you’ll find more examples.
Also see: La Petite Lesson En Franglais