3 Pixel Art Techniques for Beginners

MortMort : This is a great video about the terms ‘doubles’ and ‘jaggies’ and how to create clean overall pixel art. Something that a lot of new beginners forget to do is enable the “pixel perfect” tool in Aseprite as this will ensure your lines are always one pixel wide and maintain the clean outline. You can easily achieve a perfect outline around your sprite by using the Shift + O keybinds to open the ‘Outline’ window and it will apply to the whole sprite on the layer(s). This will also apply to all the frames/layer(s) you want to apply to just by selecting everything you want and using the same window to apply them.

Source: 3 PixelArt Techniques/Common Mistakes (Doubles, Jaggies & Outline) (Tutorial for Beginners)