A beautiful image can still fail preflight. Production-ready artwork is designed for a specific physical size, print method, material, and finishing process.
Short answer
Start with the approved product template. Check physical dimensions, effective resolution, bleed, safe zones, transparency, color expectations, text, and export settings. Keep the editable source file and validate a sample when appearance matters.
Do not build a universal file and assume it will fit every product. Templates show the printable area, final edge, bleed, safety zones, seams, holes, folds, and hardware.
Pixel dimensions only become meaningful when connected to an output size. Never “improve” a small source by changing only the resolution metadata; that does not create new detail.
Extend backgrounds into bleed, but keep critical text, faces, and logos inside the safe area. Transparent backgrounds need clean edges without halos or stray pixels.