A clean and well-groomed cat has a better chance of getting adopted, so brush your foster cat regularly, especially if he has longer hair. Contact the foster coordinator if you feel that your foster cat needs to see a professional groomer. If you are comfortable with it, you can trim his nails. But please be careful because you can cause pain and bleeding if you trim the nails too short.
Cats don’t generally like being bathed, so please don’t give your foster cat any baths.