Somebody landing on your product page from an ad has four questions and asks them in a fixed order. Is this the right thing for me? What is it actually like? Why should I believe you? What else do I need? A page that answers those four in that order converts better than a prettier page that answers them out of sequence, and most themes ship in the wrong sequence by default.
What follows is the order, and what belongs in each part. Portrelle is our own skincare label and it is built exactly this way, so every example below is a real section on a live store rather than a principle.
Above the fold: is this for me?
The gallery, the name, the price, and the three or four attributes that decide fit. On a skincare product those are skin type, texture and when you use it. On clothing they are fit, fabric and sizing. Put them as short chips a person can read in a second, not as a paragraph. If somebody has to scroll to find out whether the product suits them, a share of your traffic leaves before the question is answered.
The gallery matters more than it gets credit for. Thumbnails should swap instantly with no reload and no layout shift, because a jumping page during the first three seconds is read as a broken page.
Then: what is it actually like?
This is where a wall of ingredient or specification copy kills pages. Tab it or split it, so the argument is available without being imposed. Portrelle uses a tabbed "why it works for you" block for the technical case and a separate split panel for how it feels, because photography cannot carry texture and a bullet list cannot either.
Every unanswered objection on a product page is a refund of your ad spend, paid to nobody.
Then: why should I believe you?
Reviews belong on the product page, at the point of decision, not on a separate page nobody visits. Underneath them, the objections. Every category has three or four things that stop a first order: how long it takes to work, what happens if it does not suit me, whether it is safe with something else I use, how long delivery takes. Put them in accordions on the page and answer them plainly. Every one you leave to the customer's imagination gets answered pessimistically.
Then: what else do I need?
This is the section most stores get wrong by making it a suggestion carousel. What works is a checkbox upsell with a live running total and a single add button, so the customer sees the new total change as they tick, and one action puts the whole set in the basket. The equivalent for bundles is showing the arithmetic: what the items cost bought separately, next to the set price, on the card. Asking somebody to trust that a bundle saves money is a worse offer than showing them that it does.
And then get out of the way
The add to basket should not navigate anywhere. A cart drawer keeps the customer on the page they were buying from, which matters because the second item is far more likely to be added from a product page than from a cart page. Pin the free shipping progress to it if you have a threshold, counting up rather than counting down.
How to know which part of yours is failing
Add to basket rate against sessions tells you whether the page is selling. Basket to checkout rate tells you whether the basket is. If people arrive and leave without adding, the problem is above the fold or in the objections. If they add and never check out, it is shipping cost, delivery time or payment options, and no product page rewrite will fix it. That distinction is the whole diagnosis, and it separates the two very different problems.
What we do with it
We build these into the theme rather than the app stack, in this order, and we read the two rates above before deciding which part to touch. The finished version is on the Portrelle build study and the service is on the CRO and website page.