Progress through the main story until you gain access to Anangham. It is shortly after you encounter Lily. Once you have access to this area, go to the port and look for the Port Anangham Salvage Point. You can buy Gold Cylinders in the nearby town. Use the Gold Cylinders at the port to get some Salvage. This is also a great way to farm gold. When you use the Gold Cylinders and an enemy spawns, make sure to defeat them to get either a Common or Rare Core Crystal approximately 80% of the time. It works even better if you have Blades with the "Salvage Master" field skill.