Have a small product catalog or need to add one or a few new products and don’t have a automated feed solution? There is good news, you can now manually add products to merchant center.
Inside Merchant Center select All products under the Products menu on the left side.
At the top of the product grid select the blue circle with a + sign in it.
Now you can add all of your product details.
In each section you can toggle to Advanced to fill out additional product details. Using the Advanced toggles you will be able to enter just about every attribute you would want to include with your product.
This is a nice addition to Merchant Center if you have a small number of products and could be used in conjunction with the Google Sheets feed option. If your product attributes like price, inventory etc are changing a lot this is not going to be a long term option but for small static catalogs this gives you another free option to add your products to Merchant Center and make those products eligible for Google Shopping Campaigns.