  Digital zero-noise extrapolation (dZNE) has emerged as a common approach for
quantum error mitigation (QEM) due to its conceptual simplicity, accessibility,
and resource efficiency. In practice, however, properly applying dZNE to extend
the computational reach of noisy quantum processors is rife with subtleties.
Here, based on literature review and original experiments on noisy simulators
and real quantum hardware, we define best practices for QEM with dZNE for each
step of the workflow, including noise amplification, execution on the quantum
device, extrapolation to the zero-noise limit, and composition with other QEM
methods. We anticipate that this effort to establish best practices for dZNE
will be extended to other QEM methods, leading to more reproducible and
rigorous calculations on noisy quantum hardware.
