I solved alot of my lighting/overlighting problems....Things like glare and, reflection
fairly simply.
I do alot of evidence photography, and, when I'm doing things like car license plates at
night, they used to "Burn-out" on me, due to the flash and, the reflective plate.
1-Buy a flash that you can put on the camera.
2-Ensure the flash has a "Bounce" feature....ie; you can move the head up and down.
3-Mount a 3X5 index card to the head, with as much overlapping as possible. For temporaty mouthing, tape will do. I superglued a strip of velcro to my flash and, to the card I lamintated, so it's semi-perm.
4-Tilt the head of the flash up, so the bottom of the card is pointed down.
5-Take pic.
The card will diffuse and, re-direct the flash so you will get planty of light, but not over expose.
You can do like I did and pay like 300 bucks for a ring flash unit (that attatches to the lense and looks all CSI) too.