How to become a better colorist?

Hey guys and girls. Today something especially for you. Some useful tips from coloring artist.
Some of you asked me about tutorial. I really wanted to write one but they are so time consuming.
So let's start.

1. Make good flats at the start. Use polygonal lasso tool in Photoshop and then Paint bucket tool, it's the most accurate method. Filling areas with brushes is wrong, believe me. You will swear to gods and scream out loud trying to later fill all these tiny holes you didn't notice white painting flats with brush.
_{Of course don't stick to this advice too much. If you have a bunch of tiny elements it's obvious that it's better to color them with hard brush than to use lasso, especially the polygonal one}

My way of doing flats is to make every particular color/character on a separate layer. For example, having two girls, sky and clouds in the picture, I make 3 groups: background, girl1, girl2. Then in each group I make layers for: sky, clouds, skin, hair, shirt, jeans... etc. May look pedantic, but taking care of it at the beginning will save your life later, when suddenly you (or your commissioning party) will decide to change the hair color of one of the girls.

EDIT There's actually even better method that I learned thanks to David aka vest. Thanks, David!

I actually have something that I'd like to throw in, and it's about having the flats broken up into separate layers so you have a set of flats for the BG, girl 1, girl 2, etc. While that works to an extent, I find that there could be some issues if you're working with flats with dozens of characters in the same shot. While the obvious solution is just putting several characters on the same layer (which I used to do), I'd actually like to share a workaround to such an issue just to see what you think.

I keep all the flats on a single layer.

Beneath that layer, I have an 'Elements' layer. That layer will have each element of the image (BG, girl 1, girl 2) as just a single fill. Therefore, if I want to adjust an entire character without having to select each and every single bit on the flats layer, I just go to the 'Elements' layer and select the entire character with a single click.

While this won't do much for saving memory when working with single character shots, it has saved my life many times when working with group shots and highly complex backgrounds.

And how to select the element using this method when it's divided into parts and not on a separate layer? You can go for Select > Color Range option. Unless you have a better idea - then please share it in comments!

If you have it on a separate layer, then You can select an entire layer all at once (with everything in it) by holding down ctrl (cmd for you mac people) then clicking either anywhere in the layer in the layers pallete for older versions of photoshop or in the little icon box for that layer for CS3 versions and higher. - really nice tip from Sean

More tips on dealing with flats and colors, from Sean:
I do each character or major component of the picture's flats on their own layer. Work on one character/component at a time using as many layers as I care to for that and then when done flatten the whole character down to one layer before starting the next one.

Additionally, because of the way I colour stuff I copy that characters/component main flats layer first before doing anything to it. That way I can select the flats bits and pieces but if I need to I have a preserved section of the flats underneath - just in case. I ditch that layer when I've finished the character.

For flats don't go for saturated colors. They will distract you and won't let focus on the whole composition. Use colors from somewhere in the middle of color window, not too bright and saturated, not too dark and dull. Try to make your picture look good on this stage. Doesn't matter that you will change these colors later on, try to match them now, on flats. It will give you an idea of where you want to go.

2. Start shading. You know the "lock transparent pixels" option, don't you? Well, I didn't. I colored my first Zenescope cover without this knowledge. Anyway, it's hell useful option. You'll find it at the top in Layers window. With this option enabled you'll be able to paint shades inside the flat color, without going outside the shape.

Try not to use only soft brush. It's easy, but gives rather crappy effect. Try various brushes, grainy and textured ones. Used properly they will help you get rid of the plastic look on everything.

For shading don't use dodge and burn tool. They will give your coloring rather dummy look. Use similar colors from the same palette, but not exactly the same hue. If you have a beige skin, for example, make highlights not only brighter, but also more into red/pink shade. And shadows more into bronzes. This way it will look more natural than just light beige/medium beige/dark beige shading.
One more trick, rather advanced. If you make shadows in warm colors, make highlights in cold ones. And if you make shadows cold, make highlights warm.

vest:
Remember, all light and shadow has color, no matter what. Black and white do not occur naturally, they are just projections of existing color our eyes cannot detect, a particular wavelength on the light spectrum that's beyond our eye's capability to see.

Comic art is full of contrasts, lots of black, inked elements that suggest that shadows are black and highlights are the opposite white. It can be really misleading for a beginner, especially that we do use black and white, BUT to adjust the contrast, not as a shading method.

3. After it's done, think about the surrounding of your character. Is it a blue sky? Then either shadows or lights will affect some of the background colors. Not much, but adding some light blue color on low opacity for your highlight will bring your coloring a whole new dimension.

4. Study. Make lots of studies. Study other artists - Stanley Lau for his fantastic anatomy, Nei Ruffino for vivid colors, Phoenix Lu for bright, "chinese" colors, etc. There's nothing wrong in learning from others as long as you don't just pick their colors But try to learn from the best. Studying beginners will only make you repeat their mistakes.
Study good quality photos. Watch them from totally new perspective. Try to understand how the form is created by lights and shadows, what are natural shades of skin, wood, sky, metal etc. The best way to do it is just practicing. Go for as much realism as you can in your colorings and you will not want to go back to lazy airbrushing anymore

Good luck!