Male or female? It can make a big difference because women are far more likely to change their surnames.
Have they got a really common name (such as Richard Smith or Jane Taylor) or is it fairly unusual? It's a lot easier looking for someone with a rare name than for someone with a common one.
Did/do you know any relatives (or friends) of the person, who might be easier to trace than the actual person you're seeking? (e.g. if you're looking for Jane Taylor, who might have remarried and changed her name by now anyway, it might be a lot easier to search for her son Barnaby and then to ask him to put you in contact with his mother).
Have you tried 192.com?
https://www.192.com/
(Not cheap but possibly worth it)
Have you considered writing a letter to the local paper, asking if anyone remembers the person and can put you in touch with them?
(Huddersfield Examiner, Pennine Business Park, Longbow Close, Bradley Road, Huddersfield HD2 1GQ)