Is opening a salon for hairdressing, skincare, and body care prohibited (haram) or dubious (masbooh)? And what are the permissible conditions for that?

Working in hairdressing and body care can be permissible if it is limited to permissible matters. However, if it involves forbidden things such as uncovering 'awrah (private parts), or beautifying non-mahram men for women, or committing religiously prohibited acts like hair extensions, plucking eyebrows, and tattooing, then this is forbidden.