How do you use Klaviyo to upsell and manage product-specific emails?

Kalviyo works great when integrated with Shopify. For email marketing, product-specific and life-cycle emails, you can create your very own upsell or cross-sell flows on Kalviyo. Or you can use Kalviyo's built-in product review/cross-sell flow and customizable thank you flow. All you need to do is to amend the settings and add certain filters.