"Cats" don't really smell.... I recently had an outdoor cat (and before that cat, I had 2 other outdoor cats at the same time) and have an indoor cat.
- use a clean bowl every time you put out new soft/wet food (you wouldn't eat food of a day or 2 old dirty plate so why let the cat)
- don't leave wet/soft food out for more than 5-6 hours especially in hot weather, make sure it and the cats water bowl is left in a cool shaded place (if the cat isn't eating the soft food then cover the bowl with a plate or something until she/he does want to eat)
- clean the litter tray out every day and don't let pee clumps and poo sit there for most of the day... (don't bother with the under lining sheet, just have the plastic tray and litter)
- we use Sanicat Cat Litter
- put the litter tray in a room that isn't really used i.e. utility room and isn't near/close to rooms like the lounge/living room etc.
My house may have a cat smell and I have just gotten use to it... however, my house doesn't smell anywhere as bad as some other non-animal owners...
Essentially don't be lazy and you shouldn't have a "serious" smell problem.