The techniques one uses conducting students vs. professionals are surprisingly similar. Both require metaphorical and technical language in rehearsal when trying to create space for a unanimity of approach. Both are looking for the conductor to project both character and an intrinsic inspiration for and from the music. Both hate when their time is being wasted by too much talk. Both like when a conductor has a sense of humor in the middle of an intense work time. In performance and rehearsal, both like it when they sense that the conductor has a fundamental respect for their abilities and that they are being supported. They also like when they are allowed to have some artistic input, even at the earliest stages when they don't know exactly what they're doing!
Where things are different is the degree to which one has to teach. Students from early levels need more hands-on technical support. The older they get, of course the less you have to teach fundamentals. As you go along to the professional ranks, the musical thought requires a more precise understanding of macro and micro information to rehearse effectively, although in truth, you must think deeply about a score if you are going to project any sort of authority when putting a piece together at every level. Everyone always knows whether or not you are totally prepared or not, and I've found that if my preparation has been lax, then there will always be a question posed that can present problems from beginning musicians to those who are world class.
Simon Rattle once said that his greatest fear was being "found out." In other words, that he wasn't really competent to stand in front of a group of musicians. I think that at some level, all conductors, whether working with students or pros, if caring, truly honest, and respectful of music's depth, do have thoughts such as this. The ones who don't I usually find a bit insular and their music making cold.
The aspect of working with both groups that translates most thoughtfully is the idea of collaborative process. I have had many musicians, both pro and student come up and say, "I really enjoyed working under you." I bristle when I hear this, not because I'm not grateful for the sentiment, but because I truly consider this a process where we are working together! And this goes again for every level of musician.
Both students and pros require strong personal skills, and warmth combined with competence can make every experience incredibly rich. In the end, while the needs of both groups can be varied on a technical plane, the musical side is strikingly similar and the result can be equally moving even if the musical is executed on different levels, because if the feeling is there behind the notes, it's always transformative.