In cases of a small hole, both hand-darning and a patch are fine solutions. Since hand-darning takes a bit longer, and this hole was in a location that wouldn't be seen, I decided to go with a patch. When adding a patch, it's important to match the fabric type/ weight to the garment you're attaching it to (unless you're going for a more stylistic approach). For this piece, I used a thin, cotton knit and matched the directions of stretch.
Before
After
The patch is basted on the inside of the hole, wrong side up, to hold it in place without having pins get in the way when machine-sewing
View of the trimmed down patch from inside. A zig-zag stitch was used to secure the edges of the hole, to prevent further fraying