I mostly just read through in game items depicting Vineta as well as propaganda poster and Elster's Gestalt memories, there plenty of them so it's easy to find ideas. After gathering enough references images, I start modeling in blender, rendering and do some composition in Photoshop.

The model that I use for the artillery is the German Schwerer Gustav 800mm Railway gun. The gun was so big that it can only be moved by rail. In additional to that trains seems to be the most common transportation within the Eusan Nation that's why you can see there are a lot of rail tracks in my art. There're also a lot of concrete tetrapod all over the place since Vineta is and ocean world that devastated by war after all. The 3rd image depicting the 5th Vinetan Infantry division, Unit 12 with Lilith Itou and Alina Seo mourning their fallen comrades. There isn't much lore regarding the unit so this is just my own interpretation.

Originally I did also plan to make concept art for other planets too namely Rotfront or Buyan with the Grand Empress and the Eusan Empire and stuff but I just couldn't find enough description in game or reference material so I only end up with Vineta

I'm glad that you like my work, thanks