What's up? This is the most common greeting among young people
Así es la onda Mexicana
That's the mexican way/style
Le tiró la onda.
He/She came on to him/her
¿Cual es tu onda?
What interests you/what are you like/what do you do?
!Que Buena Onda!
That rules! What a nice person/action!
Que mala Onda
What a shame, What a reprehensible person/action