London is IMHO one of the best cities in the world for indulging in commercial sex. The crime rate is very low compared to other major cities, especially in the central tourist areas. The women are also (in my experience) friendly and eager to please, provided you treat them with the respect they deserve.
While prostitution is technically legal, there are a number of restrictions which can make it difficult to work legally. Brothels, streetwalking and kerb-crawling are illegal, but there are no prohibitions against a girl working solo from her home. More than one girl in an apartment is considered a brothel, however, and would be illegal. There are a few co-ops in which a group of working girls gets together and rents a flat, then they take turns working one day each. This falls within the boundaries of the law.
The point here is that visiting a prostitute in a flat or having a girl come to your hotel room will not put you in danger of an unpleasant encounter with the Metropolitan Police.
First of all, avoid any woman who approaches you on the street. Not only is this illegal, but more often than not is a blatant ripoff - the girl asks you for a "deposit", then disappears never to be seen again.
A more potentially costly ripoff are the Soho clip joints. This is an establishment that purports to be a live sex show, peepshow, "bed show", etc. They usually have touts calling out to passersby. If you go in you'll find only that you'll be charged outrageous prices for drinks, the "company" of the hostess, etc, and quite often threatened with bodily harm if you refuse to pay. Avoid all these places like the plague.
Found mainly in the Soho and Chinatown areas, although there are a few in Shepherd Market, these are apartment buildings with their front doors left open, and signs saying things like "Busty young model, 2nd Floor" taped to the walls just inside where people walking past on the pavement can see them.
These are generally the least expensive prostitutes, with services starting as low as £20. Walking up and ringing the bell does not obligate you in any way to do business with the girl; you can simply ask to see her and find out her rates for services, so you can decide whether or not she appeals to you. If she doesn't, just say that you were merely finding out what services she provides and you may return later. If she gets angry or comes off with an attitude, you probably wouldn't want to visit with her anyway.
The best area to find walkups is Soho, along Old Compton Street between Charing Cross Road and Wardour Street, as well as the narrow streets just above the Raymond Revue Bar - Berwick Street, Peter Street, Duck Lane, etc.
The Chinatown area also has a few, generally along Lisle Street, which is one of the "back streets" of Chinatown, where incidentally some of London's best Chinese food is to be found. There are sometimes a few walkups open in Shepherd Market, which consists of a few streets and alleyways just north of Piccadilly and south of Curzon Street, just below Mayfair.
For all their seedy and run-down appearance, the walkups are perfectly safe; you aren't going to be set upon by human gorillas and forcibly relieved of your wallet.
Walking almost anywhere in Central London, you will notice cards stuck to the insides of public telephones. In some areas the phone booth will be so thoroughly plastered with cards that it is quite impossible to see out the windows.
These cards advertise a vast array of services. Many have a photograph on them, which you can safely assume is NOT really of the girl whose card it is. If you ring the number on the card, they will give you directions to her flat. From there, things work much the same as a walkup; you can meet the girl (if she isn't busy with another client) and see if you like her.
Prices can be as low as £20, but generally start about £40 and go up, with a full hour generally costing at least £100.
Most of these ladies have a flat for conducting business, but many of them are available for hotel visits and some only do visiting.
There are a number of massage parlours and saunas where "extra services" are supposedly on offer. I have no personal experiences with any of these; hopefully someone will send me some field reports!
As noted earlier, the very lowest prices (and, generally, the lowest quality) are to be found in the Soho walkups, with a very quick french+sex starting at £20.
Most of the better establishments and more professional ladies will charge £50-60 for 30 minutes, and £100+ for a full hour.
Always be very clear on exactly what you're going to get for your money. Some ladies charge by the activity, and some charge strictly for time. Unless otherwise stated, you will probably be allowed only one orgasm; and if you do that after only five minutes, too bad, out you go! The places (and ladies) I like the best are the ones who charge strictly by time, and whatever you can manage within that time is fine; if you finish early they will give you a nice back rub or something until your time's up. See the Field Reports section for some of my personal recommendations.
I'm just a regular bloke, one of whose hobbies happens to be commercial sex. I am not affiliated with any working girls, and I don't accept money or free services from the ladies for publishing their reviews. I'm a Londoner but live in the USA now, although I still manage to get back to England once or twice a year for the beer and wenches!