If you like to meet lovely ladies in santiago, then you better speak some spanish or you will end up with hookers. Dress well, no shorts, sneakers, bleached hippi t-shirts and no baseball caps. Don't act and stare at young girls like you have just come out of prison. Don't overspend money on her friends and family.
Anyway, start the evening at Ahi-Bar in the monumento area. This is good from thrusday till sunday. Its always full of people and you will get to talk to alot of young ladies. If its friday, saturday then simply walk over to the disco / bar right in front of you called "qejote" (not sure of spelling). there the action starts after 11pm. Must know how to dance merengue to meet girls as dominican girls love to dance and dance all night. If its a weekday then head up to UTESA university and go up to the bar on the plaza on the opposite side of the entrance to the university. On the second floor you will see a bar called "estupendo". have a few drinks there from 7pm-9:30pm. You will see alot of young girls pass by. Talk to them and invite them for drinks. Guys pay for all the drinks and food for girls in this country so don't try to go dutch on them. If the place is not happening then take a walk inside the university and ask around if they have spanish speaking courses for gringos. Acts as if you are really interested in taking a course there. They have no such courses there for gringos (at least thats what I was told) but you will get to talk to girls and attract their curiosity. They will talk to you and probably invite you to a certain place for drinks and music. Be prepared to take out a group of girls with you and pay up for all.
If you would like to see some really pretty girls then go to Plaza Internacional and walk around. Try your luck there. Then if you like to hang out in elegant jevito places, go to "francifol cafe" and "tribecca bar". You will not pick up girls there unless you look like Brad Pitt but you will like what you would see there.
I say if you like to pick up a date for the evening, hang around in UTESA university and you will certainly get lucky.
Good luck.
AZB