After Effects sub-pixel interpolation is helpful most of the time but can be a problem when working with layers that you want to remain sharp including Shape Layers and type. I often find myself moving and scaling these layers, resulting in soft edges when the layers aren’t positioned on or scaled to whole pixel values.
To force After Effects to use whole pixels we can use the MATH ROUND expression. Check out Chris Silich’s post here for more detail. I created a preset to save copying and pasting the expressions. Simply select the layer you want to force to whole pixels and apply the preset.