One of the most effective things you can do to get better results from your Shopping Campaigns is to optimise your product titles.
You need to think of the product titles on your website as being different to the titles in your product feed. The titles you have in your feed need to be more keyword rich and contain much more information than those on your site.
To do this you'll need to use some kind of feed management platform like Data Feed Watch or Go Datafeed. These let you change the titles you submit to Google without having to update anything on your website.
Here are some templates you can use to craft the perfect product title depending on what you're selling (courtesy of GoDataFeed):
Athletic and outdoors:
Home and garden:
Even if you don't have access to a feed management platform, at least look at the titles on your website and try and incorporate as many keywords as you can while keeping the titles manageable.
Many people forget about using negative keywords in Shopping Campaigns but it can be one of the best ways to improve performance and reduce wasted spend. In this video I show you how to go about finding the negatives and how to add them.