There is a public site called Packal where people exchange themes and workflows for Alfred. If you think of creating any new workflow, check there, likely someone already made it.
I have also recently come across an excellent collection by Vítor Galvão:
By the way, the same guy also sells on beautiful abstract prints on Society6:
But back to our workflows. Recently I’ve been itching to make such a workflow that would prepare the computer for a presentation/screen recording:
Here’s the result: https://github.com/chuhlomin/alfred-workflow-cast