Practitioners early in their career need volume, and models are how most people get it. Done carelessly it creates the complaints that follow people for years.
Start with the language. A model is a patient. They are receiving a medical procedure involving either a prescription-only medicine or an injectable device, from someone who is learning. The reduced fee does not reduce anything else: the consent, the assessment, the record keeping and the aftercare are identical to a full-price patient. If anything they need more attention, because the treating practitioner is less experienced.
On advertising, be careful about what you say and where. Anything promoting botulinum toxin to the public is prohibited, so a post offering discounted toxin treatments is a compliance problem regardless of who is being treated. Advertise for people interested in taking part in supervised training, describe the treatment area rather than the drug, and keep price claims away from the drug name entirely.
Say clearly that suitability is assessed and that nothing is guaranteed. People who arrive believing they are booked and are then told they are unsuitable are the most reliable source of bad reviews in this whole area. The message before they attend should make it obvious that the consultation decides.
Be honest about who is treating. A model who believes they are being treated by an experienced practitioner and discovers otherwise mid-appointment has been misled, and they will say so. Say up front that a delegate treats under supervision, and say who the supervising clinician is by role.
Screen properly rather than lightly. The temptation to take whoever is willing is strongest when you need cases, and that is exactly when standards slip. The same exclusions apply as for any patient. Someone with unrealistic expectations is not a good practice case, they are a complaint with a discount attached.
On aftercare, models often get less because the relationship feels transactional. Reverse that. Give them the same written aftercare, the same contact number and the same review appointment. If something goes wrong with a discounted treatment and the patient cannot reach anyone, the discount is what everyone will focus on.
Keep the records the same too. Same consent, same photographs, same batch numbers. A reduced fee does not create a reduced record, and if a complaint arrives the fee will not feature in whether your documentation was adequate.
Repeat models need one extra habit. People who come back regularly are useful because you can see how your work settles over time. They also accumulate product, and it is easy to lose track across several sessions with different practitioners. Keep a running total per area for anyone who returns.
Decide in advance what happens if a model needs correcting. Who pays for the hyaluronidase, who sees them, and how quickly. Agreeing that while everyone is calm is much easier than negotiating it while someone is upset about their lips.