If you don't clean it up thoroughly, the cat is likely to go again in the same spot. Clean up when your cat is not in the room. It may otherwise think its marks gets your attention! Consider redecorating after cleaning up if the spraying has been going on for a long time.

Never use bleaches or disinfectants. They smell like urine to a cat, so does anything pine, rose or lemon scented.

Use warm water with ten per cent solution of biological liquid or powder. (Another suggestion is one tablespoon of Napisan AND one tablespoon of biological washing powder to one pint of water.) Then rise the area thoroughly in cold water and let it dry or dry it with a hair dryer if time presses.

Next spray or apply some other way surgical spirit. Use a nail brush to get this into fabric and crevices. This gets rid of the fatty residues that prompt a cat to top up his own marks. Dry this off completely.

Patch-test cleaning on a small area in case it removes dyes from carpets or polish from furniture.

DIFFICULT AREAS
The edge where the skirting board meets a laminating flooring will have a pool of spray urine if the site has been used repeatedly. Use a silicon sealant between the two. Then cover with heavy varnish of the sort used to varnish boats to make a barrier between the sprayed urine pool area and the outside world.
The intersection between tiles. This too collects a pool. Clean the tiles then put the heavy boat varnish in the intersection or even over all the tile surface as well.
Cement floor. Wash and clean with a biological cleaner first and let dry out for two to three weeks. If the urine marking has gone on for ages, paint concrete floor with heavy paint as a sealant. Whether painting or not, put a sheet of heavy duty polythene (the sort builders mix concrete on) under the carpet underlay before putting on clean carpet.
Wooden plank floor. The urine pool will have been created between the planks. Lift carpet, clean boards and remove any rotten wood. Leave to dry two to three weeks. Use heavy paint as a sealant. Wait for two or three months to make marking is over. Cover the planks with a polythene sheet as a barrier before putting down new carpet. If worried, put an additional sheet of polythene between the carpet and the underlay so if the worst happens, the underlay isn't ruined and it will be easier to clean up.
Carpet cleaning. If carpet has been used for urine for a long time, consider replacing with new rather than just shampooing etc.

AFTER CLEANING
When the area is thoroughly cleaned and completely dry, spray with Feliway daily or take a plain white piece of cloth and hand this where you cat will rub on it. Careful observation will show regular rubbing places. Wait till he has rubbed on it about three times. Then hang the cloth in the place where the cat sprayed. Do this daily (or twice daily for an indoor cat) for about a month. You may need to use lots of little cloths one after the other, rotating them daily.
If you can't tell where you cat rubs, use Feliway spray obtainable from your vet. In this case, do not use Feliway spray directly on the cleaned site for 24 hours (because the cleaning methods will make the Feliway useless). To stop the cat re-using the site in this 24 hours, cover the cleaned site with cling film and then spray on the cling film. 24 hours later remove cling film and spray Feliway directly on the area.
Install a Feliway plug in for added effectiveness.

OTHER FABRICS
Send curtains etc to dry cleaners. Wash duvet covers and bed linen. With moveable mats and small carpets get these cleaned somehow if you can. Throw away if you cannot clean. Before putting these back use the white cloth or Feliway on the previously soiled area. Do not try to save money on cleaning because in the long run the more thorough you are, the cheaper it all will be. A spraying/pooing cat can cause a lot of grief and nothing is too much to stop it early on.

SPECIALIST CLEANING PRODUCTS INCLUDE
Bettaware Pet Stain Remover from catalogue.
Odourfree by Alstoe Ltd from the vet.
Total Care Odour/Stain Remover by Animalcare from your fet.
Cat Spray and Urine Staine Remover by Simple Solution from pet shops.
Ammo Cat by Aquarium Pharmaceuticals Inc. - from Pets at Home Stores.
I have not tried these. Biological washing liquid/powder solution would probably be cheaper. I would always use surgical spirit as well as any of these- just to make sure. I'd like feedback if any of these work well or don't work!
FINALLY there is a US website www.PlanetUrine.com that specialises in cleaning agents to stop smell. They will ship to the UK.