Javy starts working on increasing the AOV right on the product page. They encourage users to order more products using 3 tactics:
Using slightly different offers increases the chance one of them will be enticing enough to make users pull the trigger on them.
If the offers are attractive and users can easily skip them, you can use even three one-time offers without appearing pushy.
Javy used scarcity, exclusivity, urgency, and discounting on all of their three OTOs to make the offers hard to turn down.