I would be very interested to hear about the sequence in which photographers make decisions behind the camera, and whether the sequence I am currently following is right. So for example, assuming that fundamental camera settings such as white balance, image quality and AF points are decided in advance, then comes the big ones of mode, ISO, aperture, speed, focus and composition.

The sequence I'm following at the moment is:
a) setting the mode (nearly always AV)
b) choosing ISO based on conditions. This decision harks back to the days of film where I was told 100 for sunny days, 200 for cloud and 400 for indoors or night. Rarely will I go beyond 400 even though I know the camera is capable of much more
c) aperture is set for me by the AV setting, I simply adjust aperture until I get a speed that is not likely to create blur, 1/125 seems to be where I end up taking most of my shots
d) focus is auto
e) compose and shoot

Is this sequence "correct"? Do others have a different sequence and if so why? Using this sequence DOF becomes a bit pot luck, invariably to get 1/125 speed in low light I am at f1.4 with my 50mm and this creates a very narrow DOF. A a result I still don't feel in full control, which in turn keeps me well away from going to full manual. Your guidance would be appreciated.