First let’s start with the tools and effects that I use.
You can click the tools images for a larger view.
You can also download this tutorial in Word format here.

First and foremost, use layers for every new thing you do. That way if you make a mistake or want to change something, it is very simple to go to that layer and fix it.

I did this tutorial on a top, with shading on the boob area because that is one of the most important shading areas on a skin.

First we will start with a colored shirt, pink is what I made. I just made a quick top on a nude skin using my selection tool .

Now onto the tutorial! Remember, I basically suck at tutorials, but I did my best on this one

Step One:

I created a layer, then used my selection tool to design a quick top, it is not perfect as you can see, but I am not using it either! Lol

Step Two:

I lowered the opacity to around 45-50 so that I could see the breast and other shaded areas under the top.

Step Three:

First I chose a color one shade darker than the top and created a new layer, then using the paintbrush tool I drew on some basic shading areas. Play around here and find the best spots for your skin.

Step Four:

I chose a color about two or three shades lighter than the top and created a new layer, using the airbrush tool (play with the settings, but I had my density around 50, opacity around 90 and the size around 21, also I used a circular shape). Now brush on the areas you want highlighted. With a colored shirt it is best to do like I did, with a darker color underneath.

Step Five:

Now it is time to use the blur effect, the gaussien blur effect to be exact. I first did the darker shading with my settings set at 3, then I did the lighter area with my settings at 5.81. Again, play around with the settings till you get the effect you want. Then, an optional choice here. Use the finger tool to smudge a little, I used it for the side and the back. It is not entirely necessary but can help get the effect you want. Remember if you make a mistake while smudging, just hit your back arrow and it will undo whatever smudging you did and you can start over.

Use this same process for other parts of your skins, like pants or a skirt.

For black, you can skip step three.

Go from this:

To this:

To finally this, using the same methods as above:

Good luck!