What I found useful as a new instructor - and still do! - is to take inspiration from the DVD, chorey notes and technique section of your book. (You probably talked about this some in training, too, so also think about advice your trainer gave you for building a library of cues.)
Refer to page 101 in your manual for information on different learning styles. It sounds like your new student is someone who would benefit a lot from more "feeling" cues.
Write down some feeling cues for poses, and practice them over and over, as if you were practicing lines for a play. Think consciously about where you'll use them in class, so when the time comes, you'll know what to say, and it'll be natural, without having to think of something new and original on the spot.
For example, in triangle pose (a really hard one to mimic visually at first), an excellent follow-up cue is, "Strenghten from the legs up and lighten through your hands." Another is, "Imagine being between two panes of glass."
I think this is the hardest part of becoming a great coach! I try to work with it every class, but you will find that it gets easier with time. You'll also find that having these really effective things to say in brief phrases will keep you from over-talking. You'll be able to pace your cues more effectively, to give your students that lovely opportunity to connect with the music and their own bodies.
You're doing great to be thinking about this in the first few weeks of teaching! It'll help you build a really firm foundation to work from as you grow as an instructor. Keep up the good work!