Multiply (Light Grey or Beige), Opacity 20–40%. Avoid pure black shadows to keep it looking like a liquid. 3. Inner Shadow: Adding Internal Depth Blend Mode: Multiply Color: A soft grey or very light tan. Distance: Low (2–5 px).
: Simply double-click the empty space to the right of a layer's name in the Layers Panel . Cum Photoshop Layer Stylel
This gives the fluid "surface tension."