Your local artist who never uploads art here to talk to you about how to color and shade with only a few simple steps! This is for Paint Tool Sai, because that’s the program I’m most familiar with. If someone has a Photoshop/Krita/Etc equivalent tutorial, feel free to link it or add it in the reblogs!
1) Your Lines

Sketch your piece out and line it first. I did a simple Pearl but before I really get into it, I use this way to color most of my recent pieces that are floating around somewhere.
2) Base

Use the select pen tool and color in your lines. It will be blue, thats just so you can see what you’re selecting better. If you choose a tool that isn’t selpen or selerase while doing this, it will become a regular selection outlined with a dotted line. Once you fill in all of where you want to color, click the bucket tool and fill the whole thing in with the color that is most prominent (I typically go for filling in the skin tone no matter what though). Click “clear selection”.
3) Color

Before coloring, set the layer to “lock.” This will enable you to color and make bigger strokes without going outside the lines. That’s the purpose of bucket tool’ing the selection you made–you want a solid base otherwise the transparency will make it so you can’t color where you didn’t bucket when the layer is on lock.

This is what it should look like. Then you can color the rest on the same layer.
4) Details

Details are fun because you can add anything you want! I don’t know if anyone knows my art habit, but I like to put eyebags on chaarcters. Because why not.
To do this, make a new layer and set it to “clipping group.” This way, whatever you lay down will stick to your already existing colors and in the lines even though you’re on another layer. This is what it will look like:

5) Line Color

Skip this step if you don’t color your lines, I just thought I’d include it because I like when my lines are colored instead of having them black. Set your lineart layer to “lock” and take your brush tool and color the lines a bit darker and a hue that is slightly counter clockwise to the darkest color on the area (I color picked the darker hair shade I have, and moved the color to be darker, and slightly more pink/red than the initial one, for example).
6) Shading

Finally, to add shading, all you have to do is create a new layer, set it to “multiply” and “clipping group,” and place it on top of both the details layer and the color layer.

Take the eraser tool to the shade layer, and erase the areas where you want light to hit. Once that’s done, copy and paste the layer and put it in top of your colored lines (not necessary if you left the lines black. Black is not affected by multiply).
*Tip: depending on what kind of lighting you’re going for, use ONLY light shades of any hue. I used light pink here, the multiply setting will make the color darker. The darker you make the shading color, the darker the shadow will be. Use pink/red for dusk/dawn settings, blue/purple for night, etc. You can experiment with this to get cool results. I always move the slider counter clockwise and down to get a shade color for my details shading, the only exception being green where I slide it clockwise towards the blue. And please, try not to shade with black.