Cats in general are very shy toileters and will often only pee or poop in their litter box if it is placed in a quiet, secluded area, away from family members and other animals. The importance of your cat toileting regularly cannot be over-emphasized. Too often owners do not provide their cats with private & clean litter boxes, an unlimited supply of water or access to the outdoors. Such a lifestyle quickly leads to urinary tract disease which is very common in cats and often very debilitating. In this disease, large crystals form in your cat's bladder, which can then flow through your cat's urethra (the tube linking the bladder to the outside world) and they often become lodged and stuck! This obstruction of pee then causes a cat to become very ill and very sore, at which time veterinary intervention is the only option.
The key to preventing this problem is to encourage your cat to drink more and to pee more! This helps prevent the formation of the crystals in the bladder in the first place! Ensure that you have a couple of full water bowls for your cat around the house as well as outside. Your cat should have an unlimited supply of water. As for toileting, you will need to encourage your cat to pee by ensuring privacy and security when he does so. In general, there should be more than one litter box in your household. In fact, the generally accepted formula for the best number of litter boxes for your household is, one per cat you own, plus one. So, if you have 2 cats, you should have 3 litter boxes around the house, while if you only have one cat, have 2 litter boxes - and so on. Just as important is that you use a good absorbable litter that your cat likes and that you regularly replace this litter once every 2 - 3 days (rather than once a week!). The cleaner the litter, the more your cat will want to toilet on it. Then when placing the litter boxes around the house, it is important to ensure that they are in a secluded area away from a busy area of the house - however make sure you don't leave a litter tray in a corner, or anywhere where your cat may feel trapped while he is trying to toilet.
The key to avoiding your cat developing urinary tract problems and toileting in inappropriate places, is to make the toileting experience as stress free for your cat as possible. By providing unlimited water, allowing some outdoors access and maintaining clean litter boxes in private areas of your house you will be providing your cat with this stress-free environment.