This is pretty basic stuff here, and it would benefit your ferret (and you) a great deal if you tried to do these things at least once every few weeks: (even more often would be better, but this is just basic) 1. Baths. My ferret isnt to crazy about baths, but they make him smell worlds better after wards and he needs them to stay clean just like us. Special ferret shampoo, conditioner, and soap can be found at you local PetSmart (or PetCo.)
2. Nails. We're not to good at keeping our ferrets nails clipped ourselves (he hates that more then baths,) so we take him to PetSmart or the local vet. Some ferrets do not struggle, and a simple pair of ferret nail clippers can be found at your local pet store. NOTE: DO NOT clip the pinkish part of a ferrets nails!! That can lead to bleeding since the pink part is where small veins are, so only clip a little bit of the tip and middle!! This is another reason why we take our ferret to the vet, just in case we make a mistake.)
3. Litter Box. Clean out a ferrets litter box every day...we've had bad experiences with bugs and the litter box... its best to clean it every day or at least every other day.
4. Waste Deoderizer. Put at least 5 pumps in a ferrets food or water bottle, and that reduces the smell of ferret poo. The brand that has works best for us is called Bi-Order (from Marshall ferret products,) but its best to try a bunch of brands to see which one works the best. (See eating 101)