I have been thinking about doing a little advertising locally with a few t-shirts for my kids (I know -- shameless) and maybe a canvas bag for myself. On the canvas bag I wanted to have my Etsy shop info on one side and the Etsy logo on the other. I had a package of T-shirt transfer paper and I designed the logos on my computer -- remembering to flip the image so the text came out readable on the transfer. 
I put a piece of flat (with out ridges) cardboard inside the canvas bag to keep it flat and protect the other side of the bag. I placed the transfer right side up and face down on the fabric and with the iron on its hottest setting without steam I ironed for close to 3 minutes. You have to be careful to get the edges to because when you peel off the paper once it cools they might not be adhered properly. I iron on the transfers for both sides before I peel off the paper or I will have problems with the transfer coming off while I iron the other side.
Once all my transfers are ironed on I let the bag cool a bit. When it is still warm to the touch I begin to carefully peel off the paper part.
Looks pretty good but I think I over did it on the ironing and it seems to have yellowed a bit.
Here is the t-shirt I did for my daughter.
