A way to organize a lot of different spaces is by adding space categories. They work similar to labels for a single post. A common use case is to identify all spaces that are expected to publish news (blog posts) now and then by using the space categorie news.
If you want to embed a list of spaces that are labelled with a certain space category, simply use the macro "Spaces by Category".
Embedding a list of spaces by category
Enter the space category by which you want to have your spaces listed. Maybe you use the category news for all spaces who publish blog posts, and you want to give your colleagues an overview over those, you'll enter news into the field.
You can enter more than one category for your list, just make sure you do that comma-separated: news, corporate
Display a subscription icon for the Personal News Feed
The Enterprise News Bundle includes a macro called Personal News Feed. It allows you as a user to combine several news feeds, i. e. spaces with blog posts in them, into one single stream of news. That macro brings its own button for selecting the spaces, so there's no need to add anything else but the Personal News Feed macro. But in case you want to display an overview over several spaces and offer the ability to add those to a Personal News Feed right away, you can check the checkbox for displaying the icon.
This is especially useful if your Confluences contains a large amount of spaces of which only a few publish news, or if you want to offer thematically curated lists.