Good luck. FWIW I was stuck in AV mode with evaluative metering for a very long time before migrating towards spot metering and manual exposure. I'm not saying I'm an expert by any means, or that my approach is foolproof, but it does firmly put me in charge of what is happening. So long as the light isn't altering wildly every 30 seconds it is a much wasier way to shoot, IMHO. Once you have your exposure dialed in (may take a couple of adjustments with reviews of the histogram in between) then you are good to go. On a day with sunny blue skies you can potentially shoot for hours without adjusting the exposure at all. The same thing might apply with a flat, dull, overcast day.
For example, a while back I was shooting some skiers coming off a ramp. Some would catch more air than others and/or the timing of my shot could include more or less snow vs sky, and some were dressed in dark suits while others were in pale colours. If I'd used automatic exposure I was likely to get a different reading from one shot to the next. Too much snow might cause underexposure of the sky and the subject. Too much sky might cause the snow to be blown. In that situation automatic exposure would have caused no end of grief. The truth is that everything and everyone was lit by the same brilliant sunshine and clear blue sky from one shot to the next, and in 40 minutes of shoting and well over 100 shots that never changed. I only needed to dial in a good manual exposure once, at the beginning, and then I was free to concentrate on focus, timing and composition, knowing my exposure was rock solid from one shot to the next.
I much prefer that approach to any sort of automatic exposure, when you are potentially always having to fiddle and compensate for the reflected light coming from the scene as opposed to the unwavering incident light falling upon it.
Of course, sometimes the light is all over the place, so Av and evaluative metering can be a convenience, but you still need to understand the overall makeup of the scene and the relative dominance of light areas vs dark (and where that focus point is aimed).
Here are a couple of examples from the ski shots, one with loads of snow in the frame and one with almost none. Both exposures are identical and both are pretty much perfectly correct. Neither of these photos has been edited other than resize (and sharpen after resize).
This was taken from a slightly diferent angle, but still in the same light. Once again the exposure is the same as the other two. The histogram is about as perfect as you can get.
