Packaging combines branding, product information and production technology. A good-looking mock-up is not yet a print-ready file. First you need to know what will actually be printed and which dieline has been approved.
1. Commercial brief
Product, audience, sales channel, price tier, competition, flavour or capacity variants. These inputs determine the hierarchy of communication.
2. Technical base
The dieline and material requirements should come from the packaging manufacturer or printer. A designer can help organise them, but should not invent the construction by eye.
3. Information system
The front must work at viewing distance, while the sides and back carry mandatory copy, instructions and technical data. Product variants should be designed as a system rather than as unrelated layouts.
4. 3D mock-up
A mock-up is useful for evaluating the composition and for marketing presentation. It does not replace a proof or dieline verification.
5. Preflight
Final colours, bleed, finishing layers, codes, small type and layer order must be checked against the specification of the actual production process.