What are your recommendations for managing and optimizing Google Shopping Campaigns?
It's harder than normal optimization because your feed is rigid and there's not as many metrics to review.
There are ways to make yourself more efficient and transparent, though. Start with what little metrics you have and try to make them more granular (campaign settings, parsing feed into subcategories, etc.).
Then use your metrics to determine if the problem is feed quality (title, description, images, etc. ) or product price related. Then decide if you can improve those things.
Just remember that it's not as easy as optimizing ads and keywords, because you can add/pause/delete those at any time. With this, you have several more layers of complexity. But you'll probably have higher rewards too, because most feeds are under-optimized.
Here is a resource might find useful: https://searchengineland.com/google-shopping-feed-optimization-speak-customers-language-write-compelling-product-titles-266170