Trying to get into grafhic design. Basically I need details on how to make the design. All I have is a idea!
Make sure each color is on a separate layer for the printing process. Screening shirts requires doing each color separately so that part is important.
The rest is up to you, make a design however big you want of whatever you want. The shirt printers can do the rest.
By the time I am done with this step, I have a very good idea about the proportions of the illustration, the pose of the character(s), composition, flow, text, etc.
After that, what comes next depends on a few things. I may sketch out a final drawing at it's full size, then scan it in for inking and coloring. I may end up inking it on paper, before scanning and coloring in the computer.
If the design is larger than I can fit in my desktop scanner, then, I will scan in the final thumnail sketch and use Adobe Illustrator's vector drawing tools to ink it. Depending on the type of design, I may color it in Illustrator, or take it into Photshop for coloring.
A lot of things to consider, for which, ultimately, the client must make some decisions, such as how many colors to use. (the more colors, the more screens must be cut, each one a separate printing step) gradiated fills, which will need a halftone screen, and others.
The next steps are very critical for a freelance designer's bottom line. The more I can do to prepare the image for printing, the less I will have to pay somone else to do it for me. Also, the more I do myself, the more I can charge my client. He can, either, pay me or the print shop to do the color separations. You do NOT have to make each color on separate layers. Illustrator and Photshop, both, have excellent color sep tools, with Illustrator's being a bit more advanced for operations like trapping, choking and text layout. For gradiated fills, halftone screens must be selected, etc.
By the time the file gets to the print service bureau, all they have to do is cut the screens. (or cast the plates, for paper printing)