Google Shopping
Google Merchant Center allows you to add your items to the shopping tab of google searches. This is free, but of course paid listings will be shown first. Still, it's a good resources to get some free reach!
Step 1: Setup Merchant Account
Visit https://merchants.google.com/ and set up an account.
The main settings you want to be sure to configure (and they make take some time to be approved) are:
Business Information
Free Listings Setup
Sales Tax
Shipping (note these can be estimates since you won't be using Google checkout)
I suggest adding shipping only for your home country to start.
Note it may take a few days for your logos and details to get approved.
Step 2: Product Spreadsheet
Some services like Square may offer an auto-generated spreadsheet, but it may not be have the updates and info you want. If you have the time, I'd suggest making a custom one.
Shopify can auto-connect to Google Merchant through the "Google & YouTube" app.
Template: https://docs.google.com/spreadsheets/d/1-IkaW2uRJ2QNE3jSPGCY3KFN1N-XG_8DtpjnQ8xPpIw/edit?usp=sharing
Here's what the fields mean:
id: A product id, can be anything but unique for each item
title: Item title
description: A few sentences, does not have formatting options
image_link: Direct link to a jpg or png image, this is your main photo
additional_image_link (optional): You can add more photos here, separate each url with a comma (,)
price: Item price with currency code
link: Link to the item page on your shop
material (optional): Something like acrylic, cotton, metal, etc.
google_product_category: Explained below
brand: Your brand name!
availability: in stock or out of stock
condition: new, refurbished, used (like new), used (good), used (fair)
gender: unisex, male, female
age_group: adult, kids, toddler, infant, newborn (note adult means 13+)
mpn: A globally unique id for your item, something like "YourBrand123".
Google Product Categories aren't really made for artists, so here's some common items that I've found close categories for:
Pins: 197
Buttons: 4179
Keychains: 175
Lanyards: 6277
Stickers: 4054
Patches: 6955
Figures: 6058
Plush: 1259
Shirts: 212
Blankets: 1985
Others can be found on https://support.google.com/merchants/answer/6324436?hl=en
Step 3: Sync Your Items
Visit https://merchants.google.com and go to Products > Feeds.
Click the Plus.
Add your target countries. I suggest starting with just your home country until it is approved, and then going back and adding it others.
Select Google Sheets.
Approve Google access to the sheet you setup earlier.
Do not set an update schedule yet!
Note that you probably will see some errors or "disapproved" items right away. Wait and then check back once the initial approval is complete, and then review any existing errors.
Once everything is approved, you can set an update schedule!