Hi Jacob,
Use subfolders. Remember to use the hreflag tag, inclufing the country code.
If you have the ccTLD domains, redirect them to the subfolder.
For example: If you have yoursite.co.uk point it to yoursite.com/uk/
Also, remember to add every subfolder to Google Search Console (Google Web Masters Tools) and declare for each one the country that is itended to.
Hope it helps.
GR.