Today I came across the adorable "Tweet of Foot" sandals at ModCloth. While they are so cute, I don't think I could ever bring myself to spend $89.99 on a pair of sandals/flip-flops. You can make a similar pair on your own for cheap. Below are some of my ideas. If, like me, you aren't a big bird fan, you could use any kind of embroidered patch.
Pink DIY sandals ($24.98 total)
$19.99 Renn Cork Wedge Sandal at Payless
$4.99 Pink sparrow patch set at Amazon
Blue DIY sandals ($9.99 total)
$6.00 Sparkle flip flop at Payless
$3.99 Blue bird patch set at JoAnn'
Black DIY sandals ($21.98 total)
$16.99 Lilliana Flat Sandal at Target
$4.99 Black sparrow patch set at Amazon
1) Determine where you want your patch to line up. If using a sparrow patch, I recommend lining up the wings with each of the toe straps so they somewhat hide the straps.
2) Place glue on strap where you want your patch to sit, press patch on, and let it dry completely (clamps/clips would be helpful). While I'm sure various types of glue would work, I recommend using Shoe Goo since it is made to withstand the conditions a shoe encounters.
3) (Optional) Since there is not much of a surface for the patch to adhere to, I would strongly encourage hand sewing a few stitches through the patch and strap so the patch does not fall off. If you use matching thread, your stitches will not be visible.