The first thing to acknowledge is that there’s no such thing as the ‘ideal’ way to squat, comfortable foot positioning depends heavily upon individual anatomy. Similarly, there’s a lot of conjecture around ideal and safe squat depth but the evidence is clear, there is no ideal for everyone, we aim for your femur to get at least parallel to the ground but below this is better where possible.
For the most part when squatting with a bar there’s only two holds, front and back. Indulge me here. The front squat has the bar resting on your anterior deltoids, and depending on muscle mass and upper extremity mobility this likely includes the pointy ends of your clavicles. There may be a bit of ‘self-strangulation’ for first timers but that generally passes with experience and improved mobility.
Back squat is where the contention starts. Resting the bar on your traps is considered the high bar hold, while resting it on your rear deltoids is considered the low bar hold. Essentially the difference is minimal, and mechanically they work the same. But we also know that sometimes a slight adjustment can mean the difference between success and failure. Just be sure to avoid the spinous process of C7 during a high bar hold to prevent any unnecessary pain and irritation. As for the low bar hold, ensure the person has enough rear deltoid mass and upper body mobility to hold the bar comfortably without excessively tipping forwards.
In my experience, I generally get everyone on a high bar position as this is typically the most comfortable, but I have found the low bar to be useful for people with hip and/or ankle mobility issues.
Alternatively, the front squat is also great for people with ankle issues, and is typically a more quad dominant movement. This isn’t a definitive answer, its just what worked best for the persons in question. Interestingly, being good at back squats doesn’t necessarily translate to good front squats and vice versa.