This is not something I do every day, and I keep forgetting how to do it, so I’m posting this as a self-reminder.
On a Publishing site (collection), if I need to add sub-sites based on the Team Site template:
Go to Site Settings > Look and Feel > Page Layouts and Site Templates
Add from there the Team Site or any other site template to be used
Go and create a new sub-site based on the template just added.