So, I don't know many people that went that route. Or at least not well enough to know how they went about it.
But I know a couple where she was infertile.
Anyhow, so, her husband is really into science and very methodical whereas she's very artistic, free-spirited, loves languages, travelling etc. These infos (hobbies, some info like a cv [not too detailed of course]) were included. But they did that in Spain, so, not sure about the UK, I'm not a U.K. native.
Also look wise they did their best to find somebody that resembled her. They had descriptions like pale, brown haired, blue eyes etc included.
If I was in a relationship with a woman I guess I'd think anout trying to find a 'male version' of me or her, depending on who would be the bio mum.
And if I was single I'd try to find somebody that resembled my dream husband and dream father of my children.
Not sure if that makes sense.
But as I said, I ultimately never had to look very deeply into this. So, I'm not the best person to answer this, probably.