GRD4 Macro focus trick
I've found it really frustrating to try to shoot macro wide open with the subject off center. I focus on the subject and hold the shutter release at half mast and move the camera to get the framing I want... and it's always out of focus.
Today I figured out how to do it. I set the focus mode to "follow focus" (or whatever they call it) then I focus on the subject in the center of the frame and, holding the shutter release half way down, move the framing around until it suits me, watching all the while that the focus indicator green box thingie stays with the subject that I want sharp.