For Adobe CS 5
Window/Graphic styles. In the lower left corner fly out menu, is where you find the non default styles hiding. Go to the additive library, and the style you want is called live reflect x, this flips everything you draw on the right to the left in real time. Live reflect Y will flip on top. Hold option when you click the style to activate it. It will show up in your appearance panel listed as a transform, of you want to delete it or make edits.
It reflects each line you make, so if you want something fluid like the work doodle, you will need to learn to draw everything connected. Just practice, there isn't really a good way to explain this part. You just have to have a good eye for the structure of the drawing, and good putting stuff together skills.
The flipped part of the artwork is just an instance of the artwork on the right. Use the object menu at the top and pick expand appearance. By default the to half's will be grouped, and you may see a seam in the middle. It won't print, it's just a preview issue with how illustrator displays the artwork. To fix it. use the pathfinder merge function to glue the two half's together again.
I know this all sounds very confusing, but drawing and coloring only half the drawing takes only have the time. I have cut 6hrs off my drawing time using this technique.
It dosen't work for everything, but if you need anything with symmetrical elements, this is a great way to get er done.
This part is so cool. What happens is the pathfinder merge function will use your lifework, as a cookie cutter. The Solid below the line work is the cookie dough if you like.
Squish the line work onto the solid and you are left with each little bit of artwork all nicely separated into selectable shape goodness.
This will make everything a selectable artwork. You can then just shift click to select objects and add colors to them. It's the most efficient way I have found to color in illustrator.
This is also the proper way to edit a design for a light colored shirt. Please never invert something. It swaps the light and shadow, and makes the artwork read like an ugly X ray.
I try to distribute and even amount of shades, and alternate. If you take two shades that are close together your brain will auto blend them making a third intermediate shade. Cool huh.
You can also do some trick shading by playing with the width between stokes when you are drawing. This is a flat color technique. If you like using traditional cross hatching and blending, you can do that on a separate layer and request that the screen printer half tone it for you.
The reason you want them to do it is because shirt fabrics, the screens they are printing with, and the halftones all have differing dot sizes. The printers know the best setup for their equipment, to avoid any areas where the dot's don't push threw the screens and sit on the shirt correctly. If the dot's are to small the shirt won't have anything to hold on to, and the print will fade, as those areas wear off.
But don't get discouraged with all the details. There are lots of printing methods out there. If you can make it someone out their can print it for you. Just just focus on making the best design you can.
In Screen printing each color cost time and money.
In this step you can separate your colors by merging (pathfinder merge, in cs5 it's the second row down third button in) This will cut your art into shapes.
Then ungrouping (shift, command, G) your artwork They are grouped by default after you merge.
Now use (y) magic wand tool and click on a color.
It will make a selection of anything that is the same color.
(Command G) to group your color selection.
Do this for all the colors.
This part is tricky. We are going to make new blank layers and move our colors selections to them.
Make a new layer.
Select one of your colors. When you select, you will be in the artwork layer. Doh.
Make sure you are in the blank layer you want the artwork to go to.
Then Right click your artwork, pick arrange, send to current layer.
You may have to do some back and froth ing before you get it to go where you want it.
Do this for all color selections.
Why bother you wonder.
Now that you have them all separated, you can check the artwork for tiny artifacts that need cleaning up, and add a solid shape that matches the shirt color, and see what colors you can turn on and off. If you don't need a color, don't print it. Remember it cost time and money.
Here is the mockup kit: http://arsenal.gomedia.us/distressed-shirt-mockup-templates.html
You should always try to mockup your artwork as close to the size and position of the actual printed shirt as you can. This means avoiding making it to large, or going over seams. To save on the number of screens they have to burn, the printers will make them fit to the largest size of shirt you are ordering. So made to fix XL for example. Those same screens will then be used on the other smaller sizes as well. So X, L, M, S, Xsmall
Also be carful with the blending modes you use. Multiply is the most common for light shirts, but on darker shirts it will ruin the color, so it's better to just reduce the opacity a tiny, tiny bit. You are aiming for just enough for the shadows of the shirt to show threw so the design has a nice look. This is especially important if the client is using your mockup as a temporary product shot to get pre orders.