I know, I know, I have only ordered 3 swatches from Spoonflower, so I'm no expert... but this is the lowdown:
It's very simple--
1. Make your design, and make it digital if it isn't already. If it's hand drawn you need to make sure that you scan it at the right resolution (at least 250dpi), and tidy it up in PhotoShop if need be (Spoonflower has some simpler online software to use if you don't have access to PhotoShop or the like).
2. You pick the repeat pattern, so you could centre the design in the middle of the fabric, or you let it repeat in a number of ways, such a basic repeat, a half drop or a mirrored effect. It's all very user friendly and visually easy!
3. You decide how much you want, from a little 8"x8" swatch to as much as you want-- swatches are good for checking the printed colours against the colours on your screen.
4. If you want other people to be able to buy your designs, you make them public, you need to have bought at least a swatch before you do that, it acts as a 'proof'. The customer buys the fabric at the standard Spoonflower price and 10% of the sale goes to the designer-- so you won't get rich by selling your designs this way, but you might accumulate enough to give yourself a nice discount every now and again.
All this info is available in more detail here, but I thought you might like a summary before committing!
I have made the hand drawn matroshka doll available for you to purchase. Only 1 and a half will fit on a fat quarter, but it actually doesn't cost much more to buy a yard, so maybe you could make a softie doll this way, or a pillow or something-- but please don't get all crazy, buy 20 yards and start selling them... contact me if you have commercial aspirations and we can discuss them.
Like Etsy, Spoonflower has a lot of not-so-good designs to wade through, but there are some really, really awesome designs/designers too, here are a couple of my favourites:
And there are many, many, many more designs!
Happy Friday! I won't be at Glebe tomorrow-- I have hardly any stock and it looks like miserable-thundery-rainy weather again... but I will get to sleep in and that sounds lovely to me!