I'd suggest using a regular, uncovered litter box in a secure, quiet location. Use unscented plain, scoopable cat litter and make sure it's no more than a couple inches deep. Scoop the litter box AT LEAST once per day. Also, it's a good idea to provide more than one litter box. A good guideline is the number of cats plus one. So if you only have one cat, offer 2 litter boxes. Good luck!