Well, I am not an expert in creating sprites but let's say that I have been able to understand how to make a similar style.
Very well, as a first point we have to understand what I call:

The style of 2001-2004

Here we have to understand the style of painting used by the artworks from 2001-2004, they had a painting that made the drawings seem a bit semi-realistic.
just like this:


This style has 3 types of shades in its painting. the base color, a variation of it but lighter and a darker one. and these by means of the option "Brush" in any drawing tool is achieved.


This in future years would be lost little by little, it is not that this style of painting was forgotten. a variation of this was simply made with a more anime touch.


now let's move on to the next point.

The creation of the sprite:
Now, how do we get a sprite similar to the sprites that we grew up with and love so much with?
Well, we will have to make a drawing with that style of painting from 2001-2004
Now when we have our drawing we have to reduce its size, on a 240 x 160 canvas.
but why?
easy, the sprites were works in that size because they were made for gameboy advance and they suffered almost no modification when being ported to it
a trilogy in DS.
And then we have to limit it to 16 colors.
but why?
we return to the gameboy advance.
the limit of colors for the sprites there were 16, actually 15 since 1 color was considered "transparent".

all this can be done with any image editor, in recommendation they can work with photoshop

If we follow all these steps, we will obtain a sprite similar to the ones we saw in Ds :D



and if you want just to make videos, sprites look good too



and this is the method I use to make sprites.
although sometimes the sprites will not be so defined but that is fixed manually by removing pixels and recoloring others for greater definition.
that is my contribution to the community