Within SharePoint there are various ways to generate a communication site. In release 1.5 we added the option to generate a new communication site from within the digital workspace. 

Go to the apphub and clik on the '+' sign open the addlink screen:  

Fill the fields as usual with the desired title, description, icon/image, etc; but leave the 'URL' field empty and click 'create new site'.  Click 'save'. 

When saving is completed the new communication site is visible in the apphub as a card/tile:

And when you click the tile, it opens the new communication site. And you can start to add content.