A method for drawing and colouring using Photoshop. I explain one process you can use from outlining to shading and coloring using this popular software.
There are many diffent ways of drawing/colouring in Photoshop, this tutorial will show one of them. Start by creating a new layer and draw a rough picture of your subject. This will be a guide. My subject in this tutorial is a plastic My Little Pony ^-^ lol
Create another layer behind the one you have drawn on and fill with 50% grey. This is the layer we will be mainly working on.
Using black and white with a flow value of 1 to 5%, focus on shading and highlights. To help blend, use the eydropper tool to select shades of grey from your picture to use also. Do not worry about colour at this stage.
Once you are satisfied, cut out your creation using the eraser. It helps if you create another layer behind and fill with a bright colour.
I have added hair using the same method. If your subject has hair, try using the Smudge Tool.
Go into Hue/Saturation, colourise(colorize) your picture and change the hue and saturation until you have the closest match to the main colour. I created the ponies' hair in a seperate layer so have changed it to a slightly different colour.
Using the brush tool with Mode:Hue change the colour of the things in your picture with are a different colour. In this case, I have changed the eye colour.
Use the brush tool and Mode:Hue, this time with a flow value of 1 to 5%. Add different colours to your subject to make it interesting. In this case I used yellow, blue and green - be creative!. I also used Mode:Color Burn and added some more pinks. (Afterwards, I also added symbol on her tush!)
Add your background on a seperate layer. In this case I kept it simple!
Have fun! ^-^