Various U.S. Embassies around the globe set their own procedures for the K1 Visa application although the steps for the K1 Visa petition that begins in the U.S. as detailed in this site are the standard processing for the USCIS and the NVC. Still, the nature of requirements and the elements involved in the K1 Visa application in all U.S. Embassies are the same.
It is best to prepare for the visa application phase early. Keep the snail mails, chats, e-mails, calls, or greeting cards going continuously. As much as possible, the beneficiary should communicate with the petitioner's family members or friends. That way, there are more bits of evidence of a real and reciprocated relationship between the U.S. citizen and the foreign fiance(e).