Reverse Applique T-shirt

I noticed a hole in one of my four-year-old's T-shirts a laundry cycle or two ago, and while contemplating whether to ignore it, throw out the shirt, or settle for a couple of ugly stitches, I remembered a technique I learned way back a couple of years BC (before children) called Reverse Applique. I learned it from the "Alabama Stitch Book," which I highly recommend - I borrowed my copy from the library!
In Reverse Applique, you tack a piece of contrasting fabric on the wrong side of your garment, stitch your pattern through both layers, and then carefully clip out the shape from the front of the garment.
Here's how I used the technique to replace the unsightly hole on my daughter's shirt with a much larger, but (and this is key) now decorative hole.

Materials

• Garment to decorate (must be non-fraying knit fabric - i.e. jersey knit) 
• Scrap of fabric of similar weight and weave in a contrasting color
• Thread in a contrasting color to the base garment (sewing or quilting thread would be ideal, but I always end up using two strands of embroidery floss 'cause I have so many colors.) 
• Pins and a needle
• Very sharp scissors. (Ideally tiny embroidery scissors, although since I couldn't find mine I made due with my sewing scissors.) 
• A disappearing fabric marking pen. If you don't have one, chalk or even your kid's washable markers would probably also work. 

Directions 

• Using your fabric marker, draw the pattern you plan to stitch on the front of your garment. I used a simple heart which I was able to free-hand. If you want something more complicated you can cut out a shape to use as a stencil to trace around.  You could even use fabric transfer paper, which works like carbon paper, to copy a design you've printed out.
  Hint: If you're using a disappearing marking pen, keep in mind that it will, in fact, disappear! It may not last overnight, or even more than a couple of hours, so don't draw until you're ready to stitch.
  Hint 2: It is not easy to draw on stretchy jersey knit fabric. I often end up drawing a series of dots so I don't end up dragging things out of shape. 

• Cut a piece of your contrasting backing fabric that is large enough to cover your entire design, leaving at least 1/2 inch margins all 'round. 
• Now, turn your garment inside out, and pin your backing fabric in place - again, making very sure that you overlap your design on all sides by at least 1/2 an inch. This is often the trickiest part since you can't see your design. I often end up having to correct it two or three times, but it really is important to get it Just Right. :) Also, be sure that you are not stretching either the garment or the backing fabric. 
• If desired, stretch the work area of your garment out using an embroidery hoop. I never bother. However, I usually do stick a piece of cardboard inside the shirt so I don't accidentally stitch the front and back together. 

• Using a basic running stitch, carefully stitch around your design, making sure that the stitches are small and even. Remember that you will be clipping out the inside of your design, so it is inadvisable to double back on yourself or stretch your thread across the design. 

• Now, using your sharp scissors, carefully snip a hole in the Top Layer of the fabric and cut around the interior of your shape, leaving 1/4 inch of margin from your stitching. 

• Flip the garment inside out and trim around the edges of the backing fabric. 

And that's it: you're done! 

I added a third heart on my daughter's shirt to balance the design. She was pretty excited about it!