Creating pixel art is like doing any other kind of art but using a paint program with your computer. There are numerous paint programs out there. Everyone with Microsoft has "Paint." "Corel Paint" is another. I use "Aura," by NewTek. My mouse is my brush instrument. Choosing a texture brush such as Pencil, or Chalk, etc. and adjusting the size and configuration if allowed combined with how powerful it is; controlled by transparancy allows putting colors over other colors but letting the underneath colors come through. My paintings are straightforward for the most part and include naturalistic landscapes and portraits that I do from viewing sketches and photos. It is great for painting old slides that are of failing quality and interesting enough, can be greatly enlarged without resorting to the stairstep effect in most cases.
Soon I hope to have my website up and running so you may see some of my pixelpainting.
pixelpainter