In Visual Studio, when creating a New Project, use the template for Importing from a server:
This is available for both multidimensional and for tabular. I'm guessing you're meaning multidimensional (based on saying cube) but regardless, this works for both.
You then have it create a project for you.
If it's multidimensional, just then modify the project to add another cube and redeploy.
If it's tabular, then you can't have multiple models in the one project (you can have multiples in one solution), so save it as a new name, modify it, and deploy it.