On a shelf, packaging has about two seconds
Before anyone reads a word on your box or pouch, they've already reacted to its shape, color, and contrast against everything next to it. That two-second reaction is doing most of the actual selling — the ingredients list and the tagline only get read by people who already decided to pick it up.
Hierarchy matters more than decoration
A package that tries to say everything at once says nothing. The strongest packaging design usually has one dominant element (the name, the product photo, or a single bold color block) and everything else — certifications, weight, secondary claims — pushed down in visual weight so it doesn't compete.
Dielines are not optional detail
A flat design can look perfect on screen and fail completely once it's folded, because text lands on a fold line or a logo splits across two panels. Real packaging design is built against the dieline (the flat cut-and-fold template) from the first draft, not adjusted to fit it afterward.
What to check before approving a design
Print it flat at real size if you can, even on plain paper, and fold it. Check the barcode has clear space around it, check any small print is actually legible at arm's length, and check the design still reads correctly in black-and-white photocopy — some retailers and directories will show it that way.