In Planable you can create, preview, and collaborate on any type of generic content. First, create a universal content page. You can create a separate page for each channel you use (ex. blog articles, newsletters, etc.) or different types of content (ex. guest post articles, briefs, etc.)
To create a new page, go to "Add pages" and select the last icon on the right for "Universal content".
Give it a relevant name, choose a specific color, an icon to help you easily navigate your pages, and the style for your content.
Once you're done you can start creating your content.
If you ever need to edit any of your page's details, hover over it and click the "settings" gear. From there, you can update all the information you need.