As with all things it depends on the light. When I'm out and about shooting, I tend to focus on the composition and making sure my subject is in focus. Based on the type of light I'm using, I may decide to shoot in manual, indoors with consistent light controlling aperture (always), shutter speed and iso. But if it is a partly cloudy day and clouds are passing over the sun and then just as quickly going passed, then I will go with aperture priority and rely on the camera to pay attention that the sun was just covered up by 1/2 a cloud. Otherwise, I'll wind up with images that are either blown out and overexposed or underexposed.
Then there are times where I will just focus on shutter speed and aperture and I let the iso vary. I've done that before.. .but I don't recall the situation.
For the longest time, I shot only in .jpg... and that wasn't because I was lazy, but because I didn't have software that recognized .cr2. Then i got LR4 and I couldn't figure out how to import... Click and drag didn't work and neither did open with lr when I right clicked. It was annoying... but after I did... then that is all I shoot in now.
So as with most things, it is a learning curve. I can proudly say, I have never shot in full auto.