Most product page advice is a list of elements to add. The better question is which doubt each
A product page exists to resolve doubts, so the design question is which doubts your category actually produces.
Images do most of the persuading, and scale reference is the single most commonly missing element.
Everything competing with the buy decision above the fold is costing you something, including well-intentioned trust badges.
Mobile is not a smaller version of desktop — the buy box being pushed below a tall gallery is the most common mobile conversion leak.
The product image, the title, the price, the variant selector and the add-to-cart button. That is the decision apparatus.
The full guide has the formats, the deadlines and the worked examples.