There are two ways to pixel, one is precisely 1px by 1px,
or scribble it out. If you scribbled it out, this tutorial will explain
how to clean it to make it clear, like:



Before and after (result)


A quick scribble in zoom in 8px, just draw and don't
focus too much on the lines yet


Now after the scribble, notice the corners


You want to make all the lines like this,
so no pixels are actually connecting each other other than a stright line


Look at the ears, the right is already
cleaned, so no pixels are connected by the side, only the tips


Clean all the lines that are connected


The final cat that is all cleaned up


Zoom out, and boom! all clean!



If you have any questions, feel free to ask me.