Open girls in Spanish unless she writes in English on her profile or mentions she speaks the language. Then spam her with attention through messages, voice messages, photos, and videos - until she actually shows up for a date. This is normal and bound to happen, especially outside of Bogota.
I cannot stress the "right neighborhoods" nit enough. You'll hear stories of robbings, kidnapping, and more in Colombia. So keep strong frame and expectations with any girls you're seeing. For example, you can stumble around hammered drunk in Zona T (Bogota), and I'd doubt you'll have an issue.
The easiest ways to avoid problems in Colombia is to live in a lovely area and not fuck prostitutes (aka prepagos). If someone who looks suspicious is walking down the street, then cross the damn street. Stumbling around anywhere in Cali, Colombia could be problematic. They love sex, but they refuse to feel like prepagos. The cooking date is a clear-cut closer in Colombia. It'll take effort, but the fun, friendly, and approachable nature of the women in this beautiful country makes the process enjoyable. The number of times my friends and I pulled one night stands in Colombia wasn't high. Instead of trying to change the culture to fit your needs - just go with the flow and play by their rules.
We both were looking for no-strings-attached affection.
Casual sex isn't all that great without some level of emotional connection and attachment. You can start communictin before you even cross the border.
I've talked more about the women in Colombia here: I spoke in-depth about the cities in Colombia tailor made to meet Colombian girls.
The fact of the matter is you can meet hot chicks in every Colombian city.
If you are planning to meet a woman at a club, a salsa club is probably the best kind of venue.
Women are typically there to dance to music that does not encourage them to grind with you, as reggaeton does.
Set up a few dates and you're already ahead of the game.
You can use Latin American Cupid dating site if you'll be traveling the region, and if you're globetrotting, use International Cupid Dating Site. You have rail thin girls, and you have the thickness.
Use profile pictures that show your blue/green eyes, blonde hair, muscular body, or well-dressed style. Women in Colombia go out at night to dance and show their stunning bodies to the world. That being said - I will give you one tip to make nightlife in Colombia much more enjoyable: don't fight it! You'll be pissed if you roll into a Colombian club with a "7" on your arm and every other guy in the club has a cuter chick than you.