Never quite mastered speaking in tongues myself (thank God!) but with my mother it tended to start with

"Ooo makka shakka onda le mia"

"Shunda ma onda mi-a" and other "shunda dialects" were also popular.

Of course, if none of this ranting matched an identifiable language this was always termed some obscure African or Native American language or a "heavenly language" (which in retrospect I feel is kind of insulting and semi-racist, really)...