Lomography is most commonly recognised in old film photographs and is used aesthetically in photographs. I will show you a quick process to achieve this ‘Lomo’ effect in GIMP!
The Olgas, Kata Tjuta - Lomo Effect
This is a very simple method to making photographs grungy, but its also a good technique to have handy in your mind for any post-processing you might do in the future!
The finished JPEG