Which focus setting?

Would you use on an Xsi and why? For general pics

uh?
- manual mode, iso 200, 1/500 sec, back button focus, (insert your favorite lens here), f/8 and be there?
...Terry

Umm... one shot for still objects, ai servo for moving objects...

I should have worded it different or better. When I shoot I sometimes have trouble getting it to focus on the area I want, I assume this is a user error

manually select one focus point, your xsi's center point is the most accurate.
...Terry