Super simple, iron-on (or sew-on) patch can be applied to clothing, head wear, backpacks, & more.
Directions for ironing on:
We'll use a shirt as our example.
Line up the patch for correct placement on the front side of the shirt. Either carefully flip the two over so that you can easily apply the iron to the inside of the shirt (and backside of the patch), and/or apply a piece of scotch tape lightly across the patch so that it can also grip the shirt before you flip over - helping to keep the patch in place. Note, you want the iron to only sit on the backside of one layer of the shirt so that it accurately melts the dried glue that comes attached to the backside of the patch. Keep the low to medium heat applied to the shirt long enough to melt the layer and bond it to the shirt. Give it a few minutes to dry again and harden for the strongest bond.
Although it isn't necessary, for the longest lasting application possible, you may decide to also include a whip stitch around the outer edge of the patch (and the shirt). Using white thread hide the added stitching.