How to use xcp-ng templates?

I wanted to simulate an infrastructure of separate services in their own VM’s for scability, so I needed to install several VM’s for each service. I saw that XO offers to use templates when creating vm’s but, until now, I have not seen any added value over using them. Looking around how templates are created, it seems that I want the installation media to have cloud-init installed, which most (all?) default iso’s don’t. It seems that I"m using the wrong iso, but I can’t find any ready to use image that includes them. How can I correctly leverage the templates and saving me the hassle of having to manually configure every vm?

I don’t really use them, I simply have a base VM for the systems I want that I clone for projects as needed.