Have you ever had someone in your studio that was a first-timer behind a microphone? Or maybe you're a first-timer yourself, I can tell you that recently I've had a few clients that had never been in a studio or behind a microphone before. It's been an interesting experience helping them building their confidence and ability to record for the first time. Encouragement is one of the most important tools you can use as an engineer to get the best out of a new artist.
When you have someone in the studio for the first time in their life it can be extremely intimidating, especially when you have some of the more expensive equipment. If you have a new artist behind the microphone, whether that be on an instrument or recording vocals, there's always that fear of "OMG I hope I don't fuck this up!" And that's a legitimate fear to have when you've never done something like this before. The key to helping them in the studio is to encourage them that they're doing well if they are actually trying for the first time, now that doesn't mean you don't be honest with them when they mess up, but there's a method to deliver the message without making them feel terrible about their performance.
One thing I do when I have a client in the "Booth" is when they mess up on their take I first point out what was done well, but then I point out what could've been potentially better. Now that's not saying to go ahead and nitpick everything about them and their performance, but what I am saying is provide positive reinforcement and focus on what they're doing right. The key to telling someone what they've done wrong and where they can improve is by pulling them out for a second, have the client take a breath, and then talk to them about their performance. Now if they're satisfied with their performance, don't force the issue, let them have that "Success!" They'll get better over time and the more they work with you, the easier for them (And YOU) it will become to make them the best they can be.
The role of an engineer/producer isn't just to capture the best performance an artist can give, you also have to play a minor role as a psychologist. You gotta learn how to help shape someone's confidence and mentality for the better. It's not easy, but you have to know how to sympathize, empathize, and teach the first-timers about what going into a studio entails. If you run a home studio like I do, that's generally a great place for a first-time artist to record. Now if you're engineering, you gotta have some decent chops in general, but the thing is you have to make the artist comfortable.
To sum up everything, the best possible thing you can do for a new, first-timer kind of client is to sympathize, empathize, and teach. You never know, you might start the development process of a Grammy-Winning artist and if you worked on that song/ep/album that won that Grammy, then you've achieved some pretty great things.