Tattoo Etiquette for Inquiries

I have an idea for a tattoo and want to ask around for different designs/styles/charges. From my understanding, every artist has their own flair and skill level. What is typically included in an inquiry (I was thinking of doing an inquiry with several artists)? I don’t want to waste their time if they draw up a sketch and I end up not going with them, but I do want to make an informed and confident decision.