A foam inlay only provides good protection if the product receives sufficient support and is still practical to remove. Therefore, design based on the actual product and packaging, not just a photo.
Create a reliable product contour
Measure the parts that determine the position. For an irregular shape, you can use a scan, technical drawing, or carefully checked outline. Always verify a known dimension before using the contour as a production file.
Consciously choose how much grip you want
A cutout that is exactly the same as the product size can be too tight or too loose. This depends on the foam type, thickness, cutting width, and the product itself. Don't blindly add a fixed clearance; instead, test several size variations.
Make the product accessible
Add a finger recess or grip zone where the user can safely grasp the product. Leave enough material around the cutout and avoid narrow strips that can tear easily.
Build depth with layers
For a deep shape, you can combine a bottom layer with one or more contour layers. Define for each layer which shape is cut and how the layers are aligned. An adhesive layer can simplify assembly if available for the chosen foam.
Test in the actual packaging
First, order a sample part and place it in the box, case, or holder it is intended for. Check product position, removability, pressure points, and available space when closing. Only then adjust the full set or production run.