Monitor the health of your gerbera daisies regularly. While they tend to be pretty hearty and need little care, once rot sets in, it can be difficult to regenerate and restore them to a healthy state.
Use garden shears to clip away dead plant growth, like dried out or rotting leaves.
Inspect the bases of the leaves for a small plug that forms when leaves are ready to fall off. Once this plug forms, you can simply brush the old leaves off the plant with your hands, requiring no cutting.
Pinch or clip off dead flowerheads as close to the base of the flower as possible. Pinching them off is easiest when the flowers have fully dried out, but if conditions are damp, this could lead to rotting. Clip them as soon as possible to avoid rot and disease.