Odin Sphere Leifthrasir - Velvet Coin Farming 

What you need:
Level 9 Gold
Maxed Flare Shot
Maxed Sling Whip
Maxed Tilt Whip
Maxed Spiral Drive
Maxed Round Flare
Divide the slim as fast as possible with Spiral Drive, then just spam Flare Shot on the slim for max coin drop rate. Use Round Flare or Tilt Whip on the Aerial Eyes as they can be annoying to deal with.