Thanks Roy for those tips. I just traded up from a 600D to a 7D, which just arrived this week. I'm already getting one or two quite nice shots around the garden, but my bif shots are, so far, hopeless, so I've applied your settings & I'll keep my fingers crossed & see if things improve.
Here are a few of my first shots of static birds, with 400mm f/5.6l, plus a bif shot of a Raven.
Cheers,
Dick