Geee.... that is an interesting question.
I found it totally depends on the back I use. My Valeos I could pick the right WB and have the tint settings at neutral, my Aptus was off by about 30 points (I had to add 30 points of magenta to get to the right tint), My CF39 I have to add a couple of points of magenta, my 384 I need to add about 30 points of magenta again.
Basic
I always try to expose so I need to lower the exposure setting with about 0,25 - to 0,50 stops.
With very dark stuff/garments I crank up the fill light (though this comes at a price since most fabric tends to be not neutral while most clients believe it is).
I always nudge up the blacks a bit with a couple of points unless there is a lot of black already there.
I keep the brightness normally at around 50% as well as the contrast at 25%. Saturation, clarity and vibrance at about 10%
These are the settings I normally try to start with. I alter at taste.
Tone Curve; I mostly leave alone unless I need to lower the white point.
Detail
More interesting I find to know how people are using the detail tab with sharpening & noise reduction.
I normally keep sharpening to 35,1.0,25,0 while I do most of the sharpening at the end and based upon the desired output. This also depends on the back used, my Leafs & 384 do not need as much (pre-sharpening) as my CF39.
When using 'high' ISO I crank up the color noise reduction a lot and luminance noise a bit (80% & 50%).
HSL/Grayscale
Is anyone using these? I normally do all my color adjustments in PS. If you do what do you find to be the advantages of doing it in ACR?
Split toning
Same for split toning. Is anyone using these? If you do what do you find to be the advantages of doing it in ACR?
Lens corrections & camera calibration
Anyone using these, did anyone calibrate his back in ACR?
I use ACR mostly to prep a file to be ready to be dragged through the image processor. I work in badges, prepare 1 file representative for that badge in photoshop, create an action or droplet for that, drag all the others through it and than select those files that need some more handwork.
I try to automate everything that I need to do more than a couple of times. Some people keep saying every file is unique and each need to have its own approach. My approach is that every image has something in common with others and those are the things that can be automated giving you more time for other things.