T-shirt transfer paper comes in two varieties; those for dark t-shirts (the solid white background blocks out the cloth behind it) and those for light t-shirts (transparent background allows cloth to show through). I use both for various purposes, but this is a lesson in the dark t-shirt transfers as I find them more versatile.
T-shirt transfers that you print at home don’t last as long as screen printing, so I recommend using them on projects that won’t be washed often, like throw pillows, on leather, or even on cards and paper. Play around! You can iron these things to just about anything!! Although the package says you can launder these, I recommend spot cleaning or a gentle hand wash instead. After you wash your item, NEVER iron the transfer directly or it will melt; iron the backside instead.
This is how I made the pillows in the photo, but you can use any image and iron to any surface you want to try! But, if you don’t want to make them yourself, you can always just buy them here. 😉
Select and print your images on dark t-shirt transfer paper. I used botanical images from a Dover book that came with a CD packed with royalty free JPEGS. I sized them in Photoshop and created an xray version of each flower I chose.
Carefully and meticulously cut out your images using small scissors or an Xacto blade if needed. Make sure none of the white paper is left.
Slowly and carefully peel the transfer from the paper backing. Take your time; intricate cuts could tear if you are rushing through it.
Lay your image or images onto whatever you want to iron them to. If you have a lot of feathery cuts in your image, be sure to position them where you want them and make sure every bit is laying flat.
Cover the image with the paper that came with your transfers. Press with a hot dry iron, moving it in circles over the whole image, for about 2 to 3 minutes, or until the transfer has completely fused with the fabric.
Voila! The colors of your print get richer and more beautiful when the transfer is completely fused with the surface.
delia-hauser.com 
Very cool designs and work. You should look into a “weeder”, I think there may be a way to print your designs so that you don’t need to cut them out by hand!
Evan
Thanks so much Evan! If I ever have to fill a wholesale order of these pillows, I will most DEFINITELY look into that!
whoa — you must have a kickass printer. those colors are sooo vivid.