Let’s say you are building a new theme for a client. But the website is live and the client has a theme. You want to create a new template and apply it to a page or a collection. The problem is that the templates are only visible from the live theme.
How would you do it?
One way is to work in the customizer of the new theme you are building but this is not efficient in any way.
You can push your theme live and apply the template to the page and then revert back to the original theme. I don’t recommend this approach because during the time your theme is live some customers might see the new theme.
Another way would be to create the same template in the live theme and just applied it to the page you want to use it. This way you can work on the template of the new theme you are building.
The best way to preview a template without even applied it is to go to the page you want to check. It could normal page, product page, collection page etc. And add this to the URL.
After the ?view= you need to add the name of the template. This way you can preview it without even the need to apply it. Here is the whole URL if wandering where to add it.
I hope this was usefull.