Adobe Photoshop and Adobe Illustrator are the standards for graphic design and layout.
After you create your design save it as a PDF file extension. When you save it as a PDF the file can be opened with Adobe Reader which is a free program that is updated constantly and can be downloaded anytime from adobe.com. This helps in the production process because not everyone is using the latest version of Illustrator or Photoshop, if you have a newer version like CS3 and the screen printer is still using version 10 you may run into some problems because certain fonts and design techniques that you use may not be available on the older versions, sometimes your artwork will look scrambled or incomplete because the older version cannot compensate for what's missing. But when you save your artwork as a PDF file it embeds everything into the file like a jpeg picture, what you see is what you get. Also, make sure when you save the file as a PDF, make sure that you do not compress the file, that way you won't risk losing any of the picture quality of the original artwork.
Now when it comes to color matching for your designs that is something you will have to discuss with your screen printer. Screen printers in most parts of the world use the Pantone color matching system. Basically a color like Pantone 4525, let's say that it's a shade of blue that you like, when you want to duplicate this color to be used on your artwork you tell the screen printer to use Pantone 4525. Pantone makes swatch books of all their colors with the names of the colors, so when you find something you like you tell the screen printer the Pantone number of the color. The thing is, is that not all screen printers can duplicate and match all the colors. This depends on the size of the company, how many actually inks they have in-house and use. Sometimes some screen printers will give you a swatch of all the colors that they use and that's it, if you want different colors you have to pay for them to mix them and there is usually a minimum charge and run for this. Shop around, get the best quotes. But remember, when you shop around it is the same as buying a new car. Don't tell the salesman that you are here to buy a car, tell him you are looking around and getting quotes and prices.
In regards to what "carlyannef" wrote : "I would say that Corel Draw is way more professional that Adobe Photoshop... I used that in high school! Either will work, but I find Corel Draw gets better results."
"carlyannef" you think Corel Draw is the best thing around and Adobe Photoshop is obsolete because you used Corel Draw on some cheesy, meaningless, unprofessional projects that you made back in high school in order for you to graduate. Why don't you try doing some substantiated work that is actually worth a real paycheck before you impulsively type and post more of your verbal diahrrea all over the internet. Fuc_ing stupid.
Don't be a hipster, they are stuck-up annoying jerks with no dress sense. Why not be indie instead, and base your look on the original Mod bands? A hipster wears expensive vintage clothes ironically, but an indie kid wears them as a protest against third world sweatshops. A hipster wears nerd glasses as a fashion statement, not because he has any problem with his vision. Most of my own clothes come from the charity shop, or from a website like atomretro.com