Hey, but don't worry! It takes years of practice to be a great pixel artist like
Cyangmou and neither of us are there yet.
Anyways, I think you've got a good start here! I can't say this for everyone, but you're drawing your own designs from scratch and have an immediately-recognizable style! You should be a bit more careful about your color usage, though. Keep in mind that the following example is not the
only way to draw good sprites, just how I would do it.
1. To start off I put your sprite into ASEprite and checked the number of colors. Turns out, there's 32, including transparency. 32 is a nice, even number for a sprite's palette, but if you use less colors, it will be quicker to draw a sprite and the final sprite will look much cleaner. I started off by removing colors from the image's palette until I had just enough to not loose the girl's shape. How many colors other artists would remove would be their personal preference.
2. I like your outline-less style, but keep in mind that if you place your sprites over a white or black background, the colors will blend in. An outline would help with that.
3. In the 3rd step, I tweaked the palette to be a lot "softer". If you're using non-black outlines, you need to be sure that your colors have a lot less saturation. I also added some
anti-aliasing along the girl's socks and hair. Lastly, I added a bit of dithering to her hair to give it the textured look you were originally going for.