Aab, I definately don't recommend editting lttp or other simple sprites. I have seen very little good come from them. Editting doesn't really help your skills that much, unless you edit a very detailed medium sized sprite(maybe some fighter sprites, or something like that)
There are some great tutorials here:
Go here, click tutorialsIf its not in english click "English" in the menu at the top leftTry some of those, they may be of help to you. And if you really want to get good you HAVE to practice.
1.Try by first getting am idea.
2.Pixel it roughly to get the basic shape(When doing lineart
3.Figure out a light source(Try using an offset light source(one coming from the left, or right, not in the middle.)
4.Put the light colors where the light would shine, then dark colors where the shadows would be.(When you pick you colors, try messing with saturation and hue to get a nice color, dont use a high saturation on anything)
5.Then add any details you forgot earlier.(get the colors count down as low as possible while still retaining the detail, like maybe one of your darkest shade of a color could fit in the place of another color but make sure it fits in.)
6.Post you results get some critique, and edit your pixel art accordingly.
Later after you get better and learn about colors and such, to AAing and Dithering(look for tutorials if you dont know what these are) and see if you can't get better results from that. Even try some hue shifting in your pixels(Sometimes you can use a color in the place of another color that will give you interesting results(like say a blue-ish color in the place of a green-ish color) Good luck with your pixeling
