Same as Zero, said, the drawing things from memory isnt easy, i still struggle, so i look at images to relate, also makes it hard to draw from your head, imagination, not clear to work from.
If your not all to confident in your work, you can also use a graphics tablet, be proud of the work you produce, go back to pencil, and your confidence is boosted.
The more art you do, and the more techniques you learn, the more confidence you have in general, and it also reflects on your pixel art skills.
Remeber light and darks
