just had a look at your blogspot site.
Seems like you stand fairly close to a plain wall. Maybe consider making a object which you can stick on the wall (without damaging the paint of course

) that gives a contrasting pattern for the AF to lock on?
Then switch to manual focus (so the focus doesn't run about).
When you stand to pose, you will block this object out.
You do need to consider a few other points:
a) Lighting. Currently looks quite 'flat' and uninteresting. But flash photography is really a huge topic.
b) White balance. Some shots look more reddish, others are different tones. A bit disconcerting.