Heya,
I'm no master, but I've been in situations where I had to make due with venue changes, etc, last minute, recently and had to make it work. The environment was not something I'd call photogenic, as in, if it's in the composition it was distracting, straight up gross (garbage can or something), or just in general not good for a formal photograph (separate from a casual snap). There's nothing you can do to hide it, it's going to be in the photograph, you can't hide it with blur. But what you can do is craft it and direct attention with light.
So in my recent situations, I was pulled out to a high school football field on a rainy day and they wanted the ragged old bleachers, track, fence, field lights, etc in the image because they grew up with it and it was with their kids. Didn't matter that I didn't like it, it wasn't mine, so I rolled with it. But how to make it into a photograph? I dropped ambient and used a big light (600Ws with a 60" modifier at close range, at 17mm~19mm focal length) on the kids so that the attention was more the sky and the kids and their little graduation hats being tossed, less so much the old bleachers and track (also, to mask the track, we had the kids color with chalk and stuff to at least make it look less like a grimy old track). Got it done. Parents were all ecstatic. Images shared wildly, got more requests for more photos like that. I didn't like them. But again, doesn't matter, it's what they liked.
I very much disliked the location, but, it's what they wanted:

IMAGE LINK: https://flic.kr/p/UpsfU3
IMAGE LINK: https://flic.kr/p/TL3oPe
Another recent one, a maternity session, planned at the beach (they are not into intimate dreamy stuff, she wants big bold color, her wedding was a big colorful beach wedding; I used the beach wedding photos in the maternity photos to combine the moments). Well, Florida is all rain and storms right now, so we couldn't do that. They kept wanting to find an outdoor venue locally to use, but it's raining and all the places that are public and have a nice indoor appeal are full of people (because its raining). So all we could do was cancel, or try to make it work
in their house. I opted to do it in their house, and let them know that if they're not happy with it, knowing the weather circumstances, we could just do it again outside if the weather permits soon. They really wanted that beach. But, they understand thunder and lightning doesn't play nice with what they wanted. So, I walked around the house, looked at the windows, picked a big room, we moved furniture and stuff and I did what I could to hide unsightly stuff from their house and instead, used their already printed pictures and stuff on their walls in their home, and their furniture, rearranged, to do
formal maternity (they wanted group photos, dad, mom, son together). I dropped ambient in the house with the camera settings, and went wide angle with a 35mm (distortion alert!), and used speedlites (Yongnuo 560 III's placed around) to light the house where I wanted, and a speedlite (YN 560 III) on a boom stand with an umbrella (over subjects, out of FOV) to light the subjects. I was underwhelmed, but at the end of the day, once they saw the images, they were happy and didn't even want to worry about trying to go to the beach. Lights were the difference.
I struggled, I can do beach all day, but an in-house session while it's raining and the electricity blinking from the storm? Had to make something work:
IMAGE LINK: https://flic.kr/p/VjRvFA
IMAGE LINK: https://flic.kr/p/VjRvc9
IMAGE LINK: https://flic.kr/p/UZhtd7
IMAGE LINK: https://flic.kr/p/UZhszU
Ultimately, my point, is that lighting can really be a game changer, the home run, when it comes to dealing with an environment that isn't exactly great for a formal photograph. You can direct attention with light by exposing some things down and other things up. Treat everything like a studio at that point. And there are always things you cannot control in the environment. Just use light to put the focus on the subject and most people won't notice the blemishes other than people being critical (like other photogs!).
There's a difference between producing your own art and performing a service for a client. If you want business, you have to be mindful of this.
Very best,