Sacar punta literally means to sharpen, as in sharpen a pencil. However, in every day D.F. it has two very useful applications.
The first one is to mock your friends when they have just come back from the barber shop.
Hey man, they really whacked your hair off! Yeah dude, I went for a haircut and they chopped it off.
The second refers to someone's quality as an ace, razor-sharp.
Ahora si me voy a dar a la vecina, ando bien filoso. Achis achis, qué, ¿muy sacalepunta?
I think this time I'm definitely taking out the girl next door! Go right ahead Casanova.