Ask questions or just talk about different languages. Since BrainKing is an international game site supporting many languages, this board can be kind of useful.
Sequoia has all five vowels in a seven letter word.
Facetious has them in alphabetical order.
I'm told meaiou is an alternative spelling to meow, but I don't believe it.
As for consonants, hmm. How about syllables? I know a word with one syllable that has eight letters in it. It's a noun, so adding "s" will make it a nine letter word with one syllable.
That ten bird stuff further down sounds ridiculous. They're all pronounced the same. Ten is ten. A real tongue twister can make you talk funny.