How do you manage multiple posts for a single topic?

To clarify, if you are writing about a subject that would be considered to long for a single post, how do you tie all the posts together in Ghost?

Do you use a single unique tag to group them?
Put parts in the title like ‘topic title (1/4)’?
Perhaps both.
Or maybe you would just accept the length is long and keep it one long post? I guess to depends what long is to you/reader.

I have seen a few different methods just curious what you do and why?