Start with finished size, shape and information hierarchy, then add material, print and attachment constraints. This order protects readability and prevents an attractive layout from losing text to trim, folds, drill holes or special-finish tolerances. A supplied dieline should be the working boundary for every side.
Use CMYK or an agreed spot-colour method, suitable vector logos and images with enough effective resolution. Keep fonts embedded or provide outlined final text as requested. Barcodes and QR codes need a stable high-contrast area and must be tested at the actual printed dimensions.
Special processes need separate, named vector artwork. Foil, Spot UV, embossing, debossing, perforation and die-cut paths should not be represented only by a visual effect in the design file. Clear layers allow prepress to distinguish printed content from production instructions.
Follow the design guides in decision order: dimensions and folds, bleed and safe area, colour and file format, then logos, typography, codes and variable data. Finish with a full-size proof and a written specification so the visual file and intended product can be checked together.