Some people may use Photoshop or Illustrator or whatever else out of the Adobe, Corel or FOSS array of graphics software to design their designs.
But I have .NET, which now has hot reloading, and Visual Studio at my disposal. I shall therefore code my design in C-f***ing-#
This is what I used to generate cover pages for the booklet I did for some bio convention, here
And here are the results: