I find that auto white balance works as a starting point and does, in most instances, reflect the spirit if not the exact letter of the colour balance. On the other hand, if adjusting to grey card every time, the light becomes the same boring sunshine. I do find it helpful, and pleasing to the eye, to use a camera profile presets created by color checker passport. Of course that, in itself, is not colour balanced to neutral grey. That's a choice still to be made. In some difficult cases, for example, verdant rain forest scene, taking a grey card or color checker shot is very helpful to get the greens right in post.