As usual with this question, be more specific

You want to do portraits? What else? Animated sprites? Tilesets?
I strongly agree with the practice of switching apps as opposed to 'one app to rule them all', because this focuses learning better.
(eg. even though I like GIMP and Krita, I would not recommend either of them for learning pixel art because of how many non-pixel-art things they contain. When learning pixel art, it's good to use a tool that offers you *only* things related to pixel art, because you'll then spend more time fighting with the medium itself than fighting with your tool)
Grafx2 is my general recommendation (having features for both animation and tilesets, as well as a good general complement of functionality). Aseprite has more sophisticated animation, but I find actually using Aseprite clunky.
Most of the things mentioned so far have their supported platforms and free/nonfree status recorded in Retronator's graph. With the notable exception of Grafx2, which is free and available on Windows, Linux, and (I think) Mac. Has been ported to phones too but I can't vouch for how well that platform works.
Whatever you pick, I'd suggest making sure it has customizable keyboard shortcuts. They're another way to streamline your work process / remove unnecessary complications.
« Last Edit: September 01, 2018, 09:21:38 am by Ai »

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