I have been a secondary teacher for decades, and have always taken an interest in work experience, and been one of the assessors.
Places I have seen students ask about placements, or seen parents set it up for them include:
Local parks and children's activities that have been visited
Local museums and art galleries that the children know
Local charities that the family has supported, or been supported by
Local services that the family has used, hair dressers, libraries, etc
Local businesses that the family have used, bakers, green grocers, etc
Local churches, mosques, places of worship where the family is known
Local sports clubs that the family have supported
Other local families, met in parks, children's activities, voluntary work, services, etc
Both my sons did their work experience in a local park where they had spent a lot of time growing up, they did a lot of gardening, coppicing, wildlife surveying, etc . They still feel a deep connection to that local park now, years later.
I helped run a guide company for a while, and lots of parents who new each other through this helped each other out with work experience placements for each others children as well