Good evening! For those of you on this site that happen to do art of your own--and I suppose for those that don't, as well--I'd like to take a moment of your time to discuss mirroring: flipping your artwork so that its left and right edges are reversed. It may sound somewhat odd, but it can be quite beneficial in helping you improve your work, or notice inconsistencies that are detrimental to it. This is something that visual artists can utilize regardless of their chosen medium. If you happen to be a traditional artist, you can use a small mirror--you'll have to aim it at specific targets in the work itself if you happen to be strapped for space, but for a digital artist it's as simple as selecting 'flip canvas'.
It's a fairly painless technique, and you'd be amazed by the sorts of mistakes you can notice via flipping artwork. Part of the issue is due to most of us--myself included--working with our artwork at an angle that doesn't match the angle of our vision. If you've ever drawn a figure on a flat desk, only for it to appear elongated when you hold it up to your face, this may very well be the reason why. Alongside this, you become used to viewing your work from its original orientation over time, which can make a person blind to errors.
Mirroring is quite useful if your work involves symmetry of some kind--things like eyes, lips, ears, horns, etc., so if you are producing a lot of character-based work, I'd highly suggest mirroring your work from time to time to make sure everything lines up properly.
Hope this proves beneficial to someone!
Updated by Lekkiyo