We all collect some wear and tear on our kit, and eventually you'll have to deal with a popped suspender button, or a small tear due to a bramble, or a seam coming undone. Some of us know what a housewife is - and it isn't the loving person who we must ask leave when we go out onto the the field. It's a sewing kit that should be in your blanket roll or knapsack.
When you put your housewife to work, you need to know how to sew. There's a proper way to patch your uniform. Although not period, here's some instructions on how to sew on a button.