If I get the sense that the MC already has a name and backstory and a character of their own, I usually leave them close to how they look.
If it’s a blank slate character and I’m asked “my” name and appearance, I’ll make up a name and use my favorite CC characteristics. I don’t CC them to look like me, but I feel like they usually end up looking like they could be a relative of mine.
I sort of look like my details. I use the diamond face shape because it’s the smallest one and I have a small, angular face, but I feel like my face is more oval than diamond in ratio. Also my nose is somewhere between “round broad” and “defined natural.” Finally, there’s no hair color that’s quite right. It’s browner than “black dark,” but it’s also darker than “brown black.”