Start with healed results. Ask to see work after the skin has recovered, not only immediately after the procedure.
Ask how the artist chooses shape and pigment for different faces and skin tones. A strong answer should sound individualized rather than formulaic.
Ask what the healing period looks like, what aftercare is expected, and how touch-ups are handled. Maintenance is part of permanent makeup, not an afterthought.
Finally, ask yourself whether you would still want the same shape and intensity if the current trend disappeared tomorrow. Long-term work deserves long-term thinking.