its rather simple this is wat i do and iv made a couple 100 dollars from it. it helps you start off any type of clothing company
step1. gather some money and go buy a couple packs of Hanes tagless tees.(colored or no color)
step2. hit up office max and buy a pack of iron on paper.
step3. take your drawing or shirt logo and scan to the computer.( optional if allready on there)
step4. instead of normall paper print logo or design on the iron on paper.
step5. use your hanes tee shirt and iron on the logo ar drawing safely and carefully
there you go your own homemade teeshirt graphic design. to sell visit your nieghborhood churches ask them if they want custom shirts made for there church, do this for close family and friends as well. i believe this method with further all youguys future with cloths designing