Here's a few tips that Kate shared with me (and a few I looked up).
If your dreams are leaving you with red scars, get yourself a green tinted concealer and then another good, creamy concealer that's a shade lighter than your skin tone, and a matte (nothing with shimmer or glitter in it) powder to set it. Apply the green first, let it SET, then apply the creamy concealer on top. Feather the edges of the concealer out until the edges aren't noticeable. Set with the powder.
If your dreams are leaving you with lighter colored scars, skip step one and apply a concealer that's one shade
darker than your skin tone, feather, and set.
If your dreams are leaving you with bruising, pick out a salmon colored concealer or a sheer, orange colored lipstick instead of the green, and repeat the rest of the instructions.
(OOC Note: Likely triggers for mentions of torture and other dark things in the comments. Nothing in detail, though.)