Unfortunately it's fashionable for some young ladies to wear makeup designed to make them look 'all shiny and glamorous', makeup specifically intended for photography is done completely differently. On Saturday morning you can watch wedding photographers hearts sink, when as soon as the professional makeup artist has finished their work, the bride sprays on the glitter (to make her look fab)
Short answer - they're shiny on purpose, if you can't get them into positions where the light source doesn't reflect, it's down to PP skills.
If you're using on camera flash, the biggest practical diffuser is the ceiling or wall behind or to your side, the practical difference between a bare flash and something like an onboard ezybox is non existant. ETTL was made for times when the conditions are dynamic. For me, the only time to switch to manual flash is when your position and that of your subject are nigh on static.Thanks for the info.
I use TTL for speed, there is never enough time to take readings - perhaps I should try and make the time?
Would adding a larger diffuser to the flash help?
I use frequency separation, where you copy out the texture to one layer and blur the colour layer. In the colour layer use the stamp, heal or brush tool to fix the shine