Question about shading effects !

[LF Imperor]

Hi everybody,

I'm new at Spriting and I wanted to ask you (more experienced spriters) about the shading effect. What is the best program used to create this effect ?
I've already started a char by redrawing Template lines and painting it's shirt, skin and trousers. But that's what I got so far. I want now to move to the next step, which I guess it's the shading effect. I took the default colors I used to paint the shirt, the skin and the trousers and from those I made 6 extra colours (3 darker and 3 lighter) by changing the luminance (?) item.
So I ask again... Is there any program that makes this easier ? Or I should take each color I made from the defaults and paint manually ?

PS: I have Paint + PhotoFiltre. Already download GIMP but didn't know how to use it well.

PS2: I found an effect (Gradient (?)) in PF that is similar to shading, but it was totally horizontal (darker <- lighter) and not really-really like shading. It is the lighter color (white) from right-side to the darker color (black) on the left-side.

[Lauli]

You basically need a good brain and only one darker colour.

It would take a lil' too long to explain shading very detailed, just look at some LF2 sprites and see how they are shaded.