How to build non-destructive portrait retouching in Lightroom and Photoshop?

[MatthewW]

I've been building a portrait photography side business, and while I'm confident in my lighting and composition, my post-processing skills, specifically portrait retouching, are holding me back from offering a premium product. I struggle with achieving a natural look when removing blemishes or softening skin; I either overdo it, making subjects look plastic, or I'm too subtle and the edits are ineffective. For professional portrait photographers, what is your non-destructive workflow in Lightroom and Photoshop for efficient yet subtle retouching that enhances your subject without losing texture and personality, and what specific tools or techniques do you rely on for tackling challenging areas like under-eye circles or shiny skin while maintaining a realistic result?