In some Eastern European and Asian countries, guests change from their shoes into slippers provided by the host.
Some argue that if you intend to have a shoes-off policy in your home, you should keep some slippers for guests to wear. This will make them feel more comfortable and prevent embarassments such as foot odour and holes in socks.
This is a fairly good idea, but I am not so sure. If slippers are provided, then they must either be disposable plastic slippers or else slippers that can go in the washing machine. It would be quite unreasonable to expect guests to wear slippers that have been worn by somebody else that day. I am not sure whether most slippers are machine washable. Some guests might not even trust you that they really have been cleaned and may prefer to stay in bare or stocking feet.
I think the practise of providing guest slippers might be just a bit too weird for British. Many British people will have been to a house where shoes-off was required, but not many people will have been offered guest slippers to wear, unless it was in another country. I think a lot of English guests would prefer to go shoe-less, rather than wear slippers that are not their own.
I think it is a good idea to buy slippers for family and regular visitors and keep them at your house. These should be worn only by the person they are provided for. Hopefully, one's family and close friends would be delighted by this consideration.
Providing clean socks is a different matter. I would suggest keeping a supply of clean socks in different sizes by the door for guests who are not comfortable going barefoot.
I think it is very sensible to let visitors know in advance that one has a shoes-off rule in one's home. That way, they can be sure to wear socks without holes or bring their own slippers if they prefer.