If they are sold and you want to bring back the shine , try something like rejuvenate for cabinets !
Fresh coat of paint?
Isabel: PAINT! ...don't forget to prime and take off hardware for a professional look
If they are wood, clean them well with Murphy's Oil Soap. After they dry, give them a good coat of lemon oil. They will look great!
Murphy Oil Soap for cleaning is the best thing, but make sure to use it correctly: https://chemistrycachet.com/murphy-oil-soap-uses/