Say what it's for
Lead with what the product does for the buyer. Materials and dimensions matter, but only after someone cares.
Answer real questions
Think about what people ask you in person. Does it run small? How long will it last? What's it like to clean? Put those answers on the page.
Show it clearly
Clear photos on a plain background do more than clever ones. Add one photo of the product in use, so buyers can picture it in their own life.
Be honest about limits
Say who a product isn't for. If a bag won't fit a laptop, say so. Buyers trust a page more when it admits a limit, and you'll handle fewer returns.
Write for stores too
If your product can be carried, a good page sells it to stores as well as to buyers. A store owner reads it asking one question: would I put my name next to this?