Landlords here often ask for a Colombian codeudor (cosigner). As a foreigner, you usually don't have one. What worked for me in Chapinero: paying 4 months upfront in exchange for waiving codeudor. Some landlords also accept a póliza de arrendamiento (rental insurance, costs about 5% of annual rent).

Did NOT work: offering a US-based cosigner. Don't even try.