Acrylic and housepaint - usually what ever I have handyThe green one is pretty big, around 1200 x 900, the others are 600 tall. This what I actually went to uni for - graphic design actually guarantees a pay check though.
I like your renders too - I have a mate who does similar gear, but more sci fi/fantasy and erm..girls than 'gothic'.
This is his gallery on deviant art. https://laticis.deviantart.com/gallery/