I've taught something like 100 or so private or group classes since 2012, many of which dealt with retouching in Photoshop. The main thing I noticed about other users' Photoshop settings? They all kept the same default, dark interface that Photoshop comes set to. However, I don't think those settings are helping your work. Here's why.
First and foremost, let's get some technicalities out of the way. For one thing, every single human being has a slightly different perception of light and color, and every single one of those humans who owns a computer is using said computer in an environment that's different from everyone else. Second, some media productions firms, especially larger ones, have environments specifically created for optimum and consistent color and value perception, as well as color management specialists who help keep all systems reliably consistent.
That said, for those of who work on our retouching in our studios, office or at home, we often take for granted the small but important details about our work environment. While your physical environment while retouching is a subject for a future article, I've put together a super short video tutorial on changing the absolute most important aspect of Photoshop's interface: the value of the grey tool bar, palettes and windows.
As mentioned in the video, the 18% grey card we all know and love (or totally ignore) exists for a reason. 18% grey is quite color and value neutral, and as such is an ideal baseline for determining white balance. Therefore, the next logical assumption is that 18% also doesn't distract or obstruct your eye's perception of color and value when it's in direct proximity of your image.
I'm betting you've seen this optical illusion. But even if you have, try to imagine how this can radically affect your retouching approach. After all, if your mind thinks an image is too dark, simply because of it's immediate surroundings, you're going to edit it to compensate. While it will look good to you, at your desk, on your computer, in your room, it will almost certainly look different to most everyone else. Not to mention when you print it.
Before you panic, or hurriedly scroll down to the comments section to tell me you prefer a dark interface and have had nothing but success using it and therefore I have no idea what I am talking about, hear me out.
Remember, everyone is different. But more importantly, it's a new world, and your photography is almost always going to first be seen on someone's computer. Like any web designer will tell you, trying to create artistic content that's has to be viewed on tens of thousands of varying environments, platforms and devices is an enormously frustrating undertaking. The best anyone can do is try to go for the most neutral approach that, ideally, accommodates the lowest common denominator. If your image is delicately balanced to look ideal on a nice even grey background, it does not mean it will look bad on a black or a white background. It will simply look different. However, if you tailored your image to look ideal on a white, or very light, background, it could look problematic on a very dark or black background. Finding that middle groove is the best option, and often the simple adjustment of changing your interface value (brightness) setting can help you tons.
Check out some additional perception test images/animations:
Do watch the video, and let me know if you have any additional thoughts or questions on this!