(pls bear with me, cos I don't like pm and I don't want to post in his thread)
to Yanzai,
to be frankly, you have model which not so easy to handle.
before you ask someone stand in front lens,
study them, observe them,
you will find when and where is their better side to capture them.
when you view your images after you shoot, pull yourself away as a friend,
just look at the photos as if it is taken by some other people,
and the subject is like someone you don't know at all.
what do you think about the photos? does it work? does it looks good?
how to improve? this is the way for doing self critic.
beside practicing shooting people with camera, you can practicing by observe people around you everyday, see how people walking/ standing on the street, study them.
another way to learn is to look at some movie posters, book covers or classic paintings, why the photos sell? cos they they simply look nice, study them what is in common, see how the way they pose.
now back to your model, you would notice #2 feature her best for her face structure, so just go along this, and I believe if you would just leave her for awhile, let her hang around or sitting at the rock, without posing her, but you move around her, shooting some shots without asking her to look at camera, some longer shots, may have some interesting results.
hope this help.