Every beginning is difficult, so people say. Our beginning was really easy. We had everything on hand to make superb Linux T-shirts, which lasted 15 years or more.
Back in 2002, I was a secondary school student, and already a big Linux fan. My foster father had a wholesale work cloth business and they were selling wholesale t-shirts as well. Quality, cheap prices, easily available; so I had a lot of t-shirts for myself. For almost every Christmas, birthday or other event there was an extra t-shirt for me along with the presents.
They had a partner at the nearest village who could print on these t-shirts. An old man, doing this for decades, with old-fashioned screen printing technology, which lasted forever.
I decided to ask on the local Hungarian "Linux beginner" mailing list whether I'm not alone, if somebody else wants a fancy Linux T-shirt too. It is easier to cover the initial costs for screen printing if you make more pieces. There were about 200 "orders", and people sent me the money in advance to cover the costs. Some weeks later, they received their Linux T-shirts by mail. It was big work, but then I understood that I'm not alone with Linux. No less than 200 people are around here with the same hobby.
I still have and use some of these white Linux T-shirts. They are more yellow than white from the washing, but they are our first Linux shirts, and they are still ideal to use at home and have some nostalgia.