How should I structure my product URLs?
In the SEO configuration settings (catalog > search engine optimisation) you can choose whether to serve category paths in product URLs – this is the main thing you need to consider for product URLs. I would recommend using top-level product URLs (eg: domain.com/product.html rather than domain.com/category/sub-cat/product.html) as this will prevent the product being duplicated if it’s featured in more than one category.