Step 1: Develop a Theme.
Look at the featured skins on the skin page. Chances are, most of them will be based off of actual popular people, animals, or characters. You’ll rarely see a popular skin of just a normal guy.
Step 2: Work body part to body part.
This is something that’ll help you know which body part is which. Right-click the picture above, and click “Save image as…” to save and use this skin template. This skin works as a default for creating skins. This is already enlargened by x10, so editing with details is really easy, and it wouldn’t be a matter of pixalizing. A part that says “Outside” means that it’ll be the right on your left arm, and left on your right arm. “Inside” means that it’ll be the left on your left arm and right on your right arm.
Step 3: Edit it according to your theme.
I can’t help you much here… Just do what you’ve gotta do!
Step 4: Replace your original character.
Copy your creation using Ctrl+C or right-clicking and clicking Copy.
Windows Win7/Vista: Click the Start button and search %appdata%.
Windows XP or Lower: Start the Run application and search %appdata%.
Mac: Go to “User/Library/Application Support”.
Then, go to .minecraft, bin, open the minecraft.jar file with 7zip or winrar, go to the mob folder, and paste your creation using Ctrl+P.
Step 5: Test it out, fine-tune, and post!
Test it out, and if you don’t like it, just repeat the process, editing the char.png until you like it! Then show it to the world!!
I will make a video that explains this in depth, but that’s just about it! Comment your way, and it just might get up here! Also, comment your skins using this technique!