Crop to emphasize the leaf and droplets, and remove as much of the distracting background as possible. In your image, the background elements are the main problem: they’re visually busy and not attractive, so they compete with the subject instead of supporting it.

A strong crop would exclude the grey buildings/wall areas and other hard-edged shapes that pull attention away. Keep the frame tight enough that the leaf and drops clearly dominate. If any background remains, it should only be because it adds useful contrast or shape—not because it happens to be there.

One approach is a very tight crop that removes the background entirely. Another is a slightly looser crop after editing out the worst distractions and softening the background with blur, which lets the subject stand out without cropping so aggressively.

The logic is simple: remove anything uninteresting or distracting, keep anything that helps the subject, and make sure the viewer’s eye goes first to the droplets on the leaf. There’s no single “correct” crop in art, but a good crop usually simplifies the frame and strengthens the subject.