First, welcome to Pixelation! c:
When you create any representative art there are a few basic things that influence the result.
Firstly you have a mental library, a catalog of models in your brain, which is how you understand an object or form to be.
At the beginning we understand very iconic models of objects, this is symbolism, the impression of a thing.
This is where you draw almonds for eyes, or triangle noses, feet that are pointing towards and perpendicular to the camera, the list goes on.
Spotting these are really fun, it can appear subtly in even your favorite artist's work (not by choice)

As we study, we update our mental model, and we drift from our shorthand of the object towards a better understanding of how it works/exists and how it's constructed.
Through drawing we investigate our hypothesis on how well we understand a thing, and can see where it does not match up to real life.
Construction and the ability to represent what is in our mind are iterative processes that simply require work. Along with this, is the study of light, and how to render, of materials; the fields you can choose to study beyond simple construction are numerous.
Past the more scientific/analytical fields of representative art are combinations of mental factors which are far too complicated to generalize, but very fruitful to analyze and dissect on your own. These are your interests, your desires, your personal feelings. The expression that comes about through reflecting on what parts of reality you want to represent, or have a certain fetish for, will be your inherent style. This is where you will find yourself purposefully creating a shorthand for a construction, essentially deconstructing the real thing to communicate it how you want it to be seen.
On to pixel art..
Pixel art is a medium, if you evaluate each pixel in a piece of artwork, it is pixel art. This means that we will usually be working with smaller images, because it's too much of a task to check every pixel at very high image resolutions.
For Pixel art, it is more forgiving than other mediums, because it hides the artist's hand in a way like no other medium. You are working with literal "picture elements", the rawest form of manipulation available.
Pixel art itself has certain techniques that you can use to represent things in a smaller space, and it's essentially all math. Once you learn these relationships and patterns, pixel art is simple, almost automatic. However, that is just the beginning, like learning to hold a paintbrush or pen. There are many other occurrences in pixel art that are still emerging, being discovered, and researched by artists every day. Optical illusions, new ways to hide the pixel, optimization of clusters within pixel art, just check out the Ramblethread to see some loose thoughts by some members here. Pixel art is a very new medium.
There are very many talented pixel artists. But they might not be skilled artists in the general sense of the word. You may find as your critical eye develops that some of the impressive pixel artwork you once thought was amazing now has serious flaws in fields you have studied. Pixel art has a way of masking the artist's drawing ability, because it is sometimes very far from drawing. For instance, their idea of what a hand looks like may be very off model from the real thing (assuming they were aiming for a realistic hand), and they represented their idea of a hand beautifully, to the degree it is impressive, but it still communicates the wrong forms.
There is a beautiful flipside to this: because a refined pixel art process is far removed from drawing, it is easy to simply take our mental model of construction and lighting, and render them onto the canvas without flaws in our hand's execution. You do not have to struggle with paint, or ink, or graphite, or even fine motor control. You can endlessly revise without fear of destroying undoable aspects of the work, like the energy found in brush strokes, or even the physical integrity of paper.
This said you probably won't find many artists who don't draw or blob out their work before they begins the process of evaluating and refining the pixels.
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To your final question, and TL;DR (please do read,

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Pixel art techniques are few, and simple to learn. General art principles make up the vast majority of a work's success. You can draw/paint 90% of the time, pixel the other 10%, and be way better off for it. Drawing and painting update and refine your mental library, and will directly influence how well you can create pixel art in the future. Closely watch the work of a new pixel artist who is already a magnificent painter, it will be telling in their work just how much of its merit is general artistic skill and how much is pixel specific skill.