Why are you making a skin? What to you want to portray? What effect do you want to represent? At the very least, what colors have you got in mind? Once you know what you want, be sure you can visualize it. If you're working from a comic book or movie, get an example graphic to look at.
If you just have a sketch in your head, try to translate that to your image, sketch it. Make that your base that you'll fill in and fill out into the skin you want. You'll be drawing this on the computer just like any graphic, so it's good to have an idea to guide you. If you don't know what you want you will never get what you want. Wanting "a skin" is not enough. I constantly get requests for skins from guys and clans who have no real idea what they want, they just want the novelty of the skin. If you don't care what it looks like, use a skin that's already been created.
You need something to begin with. You can start with the base skin or really any other skin or skins which seem to have a good feel with what you're trying to accomplish. Or you may want to use a wire rendering for your base that can sometimes help you visualize how your skin will appear during play. Download the wire base to try it.
The reason you need to work with a base is it defines the edges you have to work in. Everything outside the edge won't matter. And you may be able to create a really great image that looks fine in 2D, but if you have to break the edges constantly, then in 3D the image will not look like your 2D at all. Yes, that means short, fat, tentacled, or whatever changes to the 2D will not work in 3D. The model defines the 2D skin and the model is the regular Quake guy.
Drawing outside the skin boundaries may be ok. Like say you want a kilt and you do the graphic in 2D and the kilt looks great, but you view it in 3D on a model and you end up with "pants." There are some ways to fake the effect and make it a bit better, and really you may decide that the pseudo-pants in the game are quite acceptable. Keep the nice 2D, use it on your clan page. But never forget the edges that can't be broken in the game model. They'll still be alteredin the game. Don't break the edges by accident, only on purpose, and you'll be fine.
There's a real problem with guys that take 2-3 skins they really think are cool, load them up into a paint program, chop what they like, and combine into one skin to get what they want. They then slap their name on it and call it theirs. This cut-n-paste stuff makes chessy skins that seldom look good, and the guys claiming to be artists basically just stole from other skins and produced no original work. NO, colorizing a skin is not original.
A good rule of thumb is if someone else could have made your skin too, pretty easily and by accident or intent, then your work is not very original. When you're drawing a skin from scratch, noone will ever do it exactly like you. When you snag stuff verbatim from other skins; anybody can do that. It's not original, and it's not yours, so don't do it.
Use other skins for ideas, sure that's how you learn, and if you want to work from part of another skin that's fine. But when it's done the work that remains should be fresh and new; it should be a unique effect and effort you can call your own.
All of the textures and skins in Quake are set to the specific Quake palette. you can use those colors and only those colors to make your skin. Using the wrong palette of colors or making it a true color RBG will make your skin appear "messed up" with wild bright colors when used in actual play. Because of this you really need to know how to use palettes.
This site is centered on using this stuff for skins only, and if you are completely clueless about how to make graphics and use palettes in general, you need to read the docs on the graphics programs before you even begin to touch skins for Quake. It's not always easy for a beginner to get started, sometimes it's damn hard, but that's life. There are thousands of sites with many thousands of pages of information on how to make general graphics and use palettes with the major graphics programs. Mine is not one of them. Sorry to be harsh about it, but I know the email will start coming in, some already has, and I'm not going to get into how to be a graphics designer. That's graphics, not skins.
Now, that said, in the Quake palette, the colors from #17 to #32 are the ones that make up the shirt colors. Anything made in those colors will change to whatever color the player's shirt is in the game. The pants are the same way and those colors are #113 to #128.
The last few colors from #241 to #256 are what are called "full bright" colors. They don't cange much in the game environment. For example if you stand in the dark with a full bright white HI! on your chest, you'll be real friendly to everyone all the time, till all the less friendly guys see you in the dark and shoot you. I find it's nice for a logo, do the logo in a good color like that and you're always IDed in a game. I've never been a guy that cared about "hiding," and I kind of like the effect of a jet black character with a clear clan logo standing out like reflective tape on a biker caught in a car's headlights at night. The enemy players you just aced will also have a better chance of rememebring who is it taking them out that way too.
There is a big choice to make when you're working with your skin: working in the 256 color palette, or in true color and convert to 256 when done. Both color sets have their benifits. With the Quake palette you know you are making it exactly as you want it, every pixel remains. With true color you can use a number of effects and filters. You can also make smudges and and blurring wherever you like with ease. But in the end you are always working with only the Quake palette and certain things will happen to your colors when it converts.
Working with the Quake palette is pretty easy. In any graphics program you load up the base skin and under the colors or palette's section you "save palette." Make sure you load that with whatever you're working with and you'll have the colors available. Kenneth Scott over at The SkinForge also has a great zip of Paint Shop Pro palettes specifically designed for skins. You can load the overall palette or subsets of palettes to work in different colors. If you work in Photoshop, you might want this PShop Quake palette in the standard ACT format. The palette's are not cross-compatible, you have to have the right program for the palette for them to work.
With true color you can run pretty much any "quickie" effect you like. A lot of guys like to use KPT gradiants, and other similar filters, but you'll find many of those don't convert well at all. For me, I happen to like the true color for the psd layers. I use them to mix and match my base components till I get the effect I want.
Neither system is really overall "better" than the other. In truth I've gone back and forth between them, and lately I will actually work in both on a particular skin at the same time. In all cases though I've found you will get much better results to work with a simple tool and draw the skin at the pixel level. Use some anti-aliasing with a pintpoint airbrush for a lot of smoothing control if you don't like to work pixel by pixel with a pencil/brush tool. Yes that's the long and tedious way to do it, but that's where the "artist" in Skin Artist comes from.
Mainly, stick with it till you get it right.
The game pulls the skin onto the model based on it's location in the graphic. You need to line everything up right, and it works form the 0,0 pixel in the top left. That being the case though you can widen the space on the right and below the skin to give you space to name and sign it. The image dimensions cannot exceed 320 pixels wide by 200 pixels tall. If you make the skin file larger than that it will not map onto the 3D skin model correctly.
Most artists use the right side, I strongly reccomend it. You can also sign the skin in the space below the boots, but you have to keep in mind that the soles of the boots are just below the skin. If you leave it black, the bottom of the boots are black. If you have text there, that text will stretch under the boot and show up whenever your guy gets blown around, walks, jumps, etc, exposing the bottoms of the boots. Sometimes it's a nice effect, sometimes it looks like crap. If you don't want it to show then you need to make the space a little larger under the skin or just use the right side.
There are alot of guys that seem to save their skin, hop into a game to use it, and all they see are these funky bright colors on their distorted. What's happened is they did not save their palette correctly (unless of course the skin was designed to look that way, but we'll not get into the wierd tastes ofsome of the artists).
You must save your skin in a standard 8 bit PCX format using the 256 color Quake palette. Don't use 64k color, 16 colors, the Windows system palette, or anything else. It will screw it up. If you are not sure if your skin is converted, do an extra "load palette" of the base skin's color set just before saving.
Do you have a problem saving the PCX with more than black and white? This is because Paint Shop Pro defaults to the Version 0 sub type which only supports two colors. Version 2 supports 16 colors, and Version 5 supports 256 colors. When you are saving the image as a PCX file change the sub type through the drop down menu option to Version 5 and it will work with the 256 color Quake palette.