Mod Before Client
Mod Before Client refers to the client's safety always coming before the coolness factor. It is an unfortunate phenomena in the younger generation of "cutters" to put a greater emphasis on the modification than the needs of the client.
For example, a mentally unstable client approaches a practitioner and requests an unsafe procedure. A practitioner that is responsible will talk the client out of the procedure (and refuse to do it, no matter what), whereas a "mod before client" practitioner will be excited enough about doing a "cool mod" to overlook the bigger problems, often even talking them into a bigger and more dangerous procedure.
The first thing a quality practitioner will do is tell you whether your procedure is safe or not (you can look up the risks yourself here on BME/Risks). If a practitioner doesn't drill these risks into you, it means either they don't know them, or they don't want to bother telling you. They're not people who you want working on you.
If your procedure is risky (example, implants on top of a forearm), the practitioner should explain to you why the procedure can't be safely done, and discuss your alternatives with you. Only the worst, most dangerous hacks will do a procedure that isn't safe "because the customer insisted." They will either work with you to develop a safe alternative, or not do the procedure at all.
In the course of discussing all this with you, they will be listening to what you're saying, and assessing whether you understand the implications of the procedure and are ready for it. If they don't think you are ready, they will — and SHOULD — tell you either that they won't do it, or that you come back later.