Pedro Medeiros, a very skilled pixel artist, had started a beginner's guide to pixel art.
How to start making pixel artAn absolute beginner’s guide
This is a little article on how to start making pixel art, intended for those who are really starting out or never even opened a pixel art software. For now I’ll cover only the very basics, how to create a file, setup the canvas size, and work with a color limit.
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Before StartingBefore jumping into pixel art, remember: pixel art is just another art medium, like guache, oil painting, pencil, sculpture or its close cousin mosaic. To make good pixel art you need to be able to make good drawings. In general, this means studying anatomy, perspective, light and shadow, color theory and even art history, as these are all essential for making good pixel art.
ToolsYou don’t need anything fancy to make good pixel art, and you can do fine even with just a good mouse and free software. My setup includes a small Wacom pen tablet, a good mouse, a good keyboard and my favorite software is Aseprite, but you should use whatever your’re most comfortable with.
Here’s a list of software commonly used for pixel art:
Aseprite: Great professional editor with many time-saving features (paid)
GraphicsGale: A classic, used in many games. It’s a little complex, but full of great features (free)
Piskel: Free online pixel art editor (free)
Photoshop: Powerful image editor not intended to make pixel art but you can set it up to use it (paid)
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Read the full article here: https://medium.com/@saintjust/how-to-start-making-pixel-art-2d1e31a5ceab
===========================================================================A compilation of all this great tutorials could be found here
http://blog.studiominiboss.com/pixelart