It is great that you have the competitor products and packaging from top sellers to compare. If you like the packaging and as a consumer-experience, it appeals to you, that is a great mark to aim for. But just as importantly, don’t over engineer packaging that is thrown away and a small feature on the packaging could be high cost and low return on investment.
Packaging is a protector of a product; it is used to communicate useful ‘usage’ information and it is also there to present your brand. So just cost out 2 different packaging options with your sourcing agent, so you can see what ‘good’ branded packaging costs and what ‘very good’ branded packaging costs. (typically when experienced sellers are looking to reduce COGS, they go back to their packaging and review any opportunity to reduce over engineered designs/packaging, because it’s only ‘nice to have’.
Just picking up on one item you mentioned:
“Insert : Instead of an instruction page and a catalog, I will put a “Thank You card” and a QR code for Free Gift.”
If I was the consumer, I would prefer a instruction page so that I can use it right away with ease.
For Listing: main picture in order to win
– Consider adding color any part of the product – a tag, a logo or the padded part of the handle would be great and this would also highlight the handle padding too, which NONE of our top 3 sellers highlight easily. Red typically stand out very well on generic black products
– If you choose a ‘pet-model’ make sure the fur color contrasts with the a black product
– You an also put ‘large dog sling’ into ‘google-images’ and see what images jump out on line that are different and unique