Post processing
Not all your black background photos are going to come out of the camera perfect for posting and many will need some processing.
Wiggle your curves: the first thing you should always do is use the luminar curve to accentuate the blacks and the highlights – make the curve S shaped and experiment.
Contrast: play with the contrast slider carefully to just see how this helps.
Blacks: play with the black slider to make some of the blacks consistently black with no greys and take out the complexities in the background.
Layers: use layers to reduce exposure of backgrounds a little bit and even desaturate areas while use a layer on the face to bring up sharpness and clarity a little.
Background removers: some software even include background removers (e.g. Luminar) which will make the process even easier. In other software (Capture One, Photoshop) its pretty easy to select the background as a layer and play around with it.
Finally consider turning your image into monochrome – you will lose any golden light or colour in the highlights, but it can make a cracking image. Most of all have fun and go and play – break the rules and be creative.