The jewelry and the beard are simple. Use the Adjustment Brush in LR and mask (yes, using the AB means you are applying a mask) the chain and the brooch. Taking those and doing the beard separately allows for more flexibility. With the chain and brooch masked, crank up the Clarity and Sharpness. That's it on those.
The beard is exactly the same. Mask off the beard area and bring up the Clarity and Sharpness. The reason for separating out the beard from the jewelry is just because there will be different amounts applied to each. Use too much on the beard and it'll get crunchy. You can probably go nuts on the chain and brooch without any harm.
I've put out a couple posts on the PS technique. It uses two different Curves Adjustment Layers. One with the curve brought up about a quarter way in from the right (whites) and the other curve is brought down about a quarter way in from the left (blacks). Reverse the Masks that are inherent with the Adjustment Layers so they're Black. You probably want to name the Adjustment Layers. I use Highlights for one and Shadows for the other. (You can probably figure out which one would be which.) Use a thin, hard white Brush (B) (about 10 pixels and 95% hardness) and draw lines on the Masks. Put a Highlight next to a Shadow (that's how definition is formed). You can see on your image where things need to be accented. Once all your lines are drawn, Blur the Mask. From 1 to 20 nothing will probably happen (dependent on resolution). At about 30 to 40 the lines will dissolve and you'll end up with lighter (or darker) areas on your image. You may have to turn the visibility of the Layer off and on a few times to see the image brighten up (actually, contrast up). If you don't see anything happening, lower the Blur a few points.