This is what I used:
shirts
fabric (for the design)
a heart stencil
scissors
Heatbond-iron on adhesive-LITE-purchased in the fabric department of JoAnns
an iron
a needle
thread
a sewing machine is optional
First, I traced the heart onto the paper side of the heatbond.
Then I ironed the fabric on to the rough side of the heatbond. I turned the steam off on my iron and made sure it adhered well.
I then cut the heart out.
Tada. (Sorry about the ugly ironing board cover background)
This is what the back of the heart looks like.
I peeled the paper coating away and was left with a smooth material on the back of my heart.
I positioned the heart on my shirt and ironed it on. I had my iron on the hottest setting possible, no steam.
The heart attached easily. You could stop here, but I wanted to do a little decorative stitching.
The fabric had a "dotted" black line running throughout it. I decided to continue that around the edges. I used a piece of embroidery floss and hand stitched around the heart. I've seen others use their sewing machines and fancy stitches but... I'm not a great seamstress and I really thought with this particular fabric, this looked cute.
In less than an hour I had two shirts done for my two girls. I like quick crafting!