Adobe PhotoShop™ is a more advanced art program than what you normally do with your computer; To use it effectively, you need to know how it works. Knowing a few ways to color, sketch, fill, outline, and shadow (all detailed in the steps below) will ensure your work is something you're proud to flaunt.
Note: If you don't have Photoshop, other free programs like Gimp are great for this tutorial.
Step
Method 1 of 7: Creating a New Document

Step 1. Open a new document of course, so you click "FILE", "NEW" and you set the dimensions

Step 2. Set the width and height dimensions, here you can see 500x500 pixels, but you choose whatever you like

Step 3. Create a layer
Once you've determined the canvas size you want, you create a new layer. First you have to click "layer" "new" "layer." And name your layer. Name it "white"

Step 4. Fill the new layer with white

Step 5. Create a new layer
Now you will start sketching what you want to draw. Click on a color and choose one.
Method 2 of 7: Sketch

Step 1. Select a brush and apply its settings

Step 2. Image
You don't have to worry about neatness, just draw! This is a sketch.
Method 3 of 7: Outline

Step 1. Give the outline
Now that you have the sketch, you need to outline it to make it neater. Create a new layer. Click the pen tool, and click "freeform pen tool"

Step 2. Outline your lines
Since the pen tool refines your lines, you may need to erase and redraw them. (not all of them, just the lines, don't worry)

Step 3. You have a line
Now you need to stroke. Right click and click "Stroke Path" and then

Step 4. Set to paintbrush or pencil

Step 5. You should have this by now

Step 6. Erase the rough sketch
Remove the old lines by doing this. Right click and select delete path.

Step 7. Repeat for all the rest of the images
Here we see this:

Step 8. Clean
You don't want those disgusting blue stripes, do you? You do this:

Step 9. You have this

Step 10. Look at the lines
Some are thick and misshapen, all we need to do is taper.

Step 11. Take an eraser and sharpen the lines by erasing the ends of the lines

Step 12. Repeat for the rest of the stripes

Step 13. Add color
Now it's time to add color.
Method 4 of 7: How To Color 1

Step 1. Go to color and choose one you like
Create a new layer Okay, now you color it!

Step 2. Move the "border" layer above the "color" layer

Step 1. Continue adding more colors
(but make sure you are still on the 'color' layer)

Step 2. Use the magic wand
Now the lines are out of the picture right? That can be fixed easily. Click "magic wand tool"

Step 3. Click on the outline layer and use magic wand and click canvas
This will happen:

Step 4. Go down to the color layer and press delete on your keyboard, the extra color disappears

Step 5. Click ctrl+D
Okay. So repeat until all your coloring is done.
Method 5 of 7: How To Color 2

Step 1. Create a new layer, and block out any areas that are not covered, such as the hands and body
(Temporary)

Step 2. Go back to your color layer
Select the area you want to color with the magic wand tool, and color it. The magic wand won't let you color outside the lines, so you need to select each area you want to color.

Step 3. Delete the "closing" layer and you'll end up with this
You may also want to revert the "border" layer on top of the "color" layer, so that the lines don't distort.
Method 6 of 7: Shadow

Step 1. Shadows and lighting Create a new layer Click the airbrush and set its opacity to 10% at the top, and choose a color darker than your original color
Use your airbrush anywhere you think there is a shadow.

Step 2. Continue with the body

Step 3. Now choose a shade that is lighter than your original color and place it where you think there is light, highlight it
Add details like the eyes.
Method 7 of 7: Done

Step 1. Final result
Tips
- Practice, it's the only way to become proficient.
- Coloring method 2 should be used when multiple layers cannot be used.
Warning
- Layers are very important in this process, so you can delete a single step without having to redo it completely. Don't mix the layers.
- Staring at a computer screen for long periods of time is unhealthy, look away for twenty seconds every twenty minutes.
Recommended Equipment
- Adobe Photoshop (Gimp or other free programs will work, but Paint will not).
- Drawing tablet (makes sketching much easier, but not mandatory).