One sewing machine. Okay, since we live in the 21st century, I'll try again: One sewing machine, and a Kickstarter with viral marketing. I am kinda serious here. If you know how to make clothes, you should just make one example piece for yourself, and if anyone compliments on them, give them your business card. Make the first few pieces custom tailored (yes, it is okay, if the first few pieces are expensive; those customers also pay extra for being unique), and if the demand grows, start doing it full-time, and later employing other people to do it for you. Just remember from the beginning that you are trying to create a brand: have a website, business cards, etc. Costs: one sewing machine, one elegant website (without anything interactive, only "send me a message"), hundred business cards, and a few pieces of clothes for you and your friends. That's what; under $1000? If you don't know how to make the clothes, make a sketch, and pay someone else to do this for you. That could be more expensive. On the other hand, if your plan succeeds, you already have a supply line, and time to focus on marketing and management.