If you have qualms about visiting trafficked women then better to avoid the shops and flats with an ever changing rota, unless it's been established that it's known girls with (good) rep touring around the UK, often on a pretty regular and cyclical routing repeating over years even. There are various networks in play.
Canny girls often keep their names consistent as they travel relying on reputation so it's worth searching around the UKP regions for a trail of info. Sadly it's not guaranteed and there are a good many changing names as they go because they're avoiding a rep, so be wary of "new" girls rotaing in with no rep.
Worth trying to determine if the establishment/management has a decent rep as these are usually going concerns that are mindful of pissing off their regulars and attracting attention from the cops if trafficking/banned activities concerns are (spuriously) raised.
Unsurprisingly call-takers may be very cagey with an unknown enquirer but once you're known to them you may well get more guidance on who to try, your luck and judgement will determine just how "honest" they prove to be. Some managements may never tell you the more accurate descriptions or feedback regardless of your years of custom but there are others who will look after you. Some mamasans can get a bit moody and anxious if business gets slow tho and they may try to tempt you in on an iffy SP.
Most Chinese will be unshaven, some do trim. If they're flirty with a bit of a twinkle then you'll likely be allowed to dine to your heart's content, they may get a bit possessive of you once you show some skill. How sanitary they are down there can be quite variable from girl to girl and day to day, another good sign is if she'll wipe once she realises your intent, though sometimes they may not wipe to the rear so if you're into "clean" smothering then you might want to be mindful lest you get a nasty pink-eye. Some girls shower after every punter, dry skin is a tell tale, but others don't so again just be aware. IF there's a shower in the room you could try suggesting an assisted shower, just another option for getting in her good books if she's game but only if there's room since they mostly won't be svelte, petite, 45kg spinners.
The elder matrons are more often hot to trot if you rev them up whilst showing good manners. +40 for b2b may well get you RO/69/FS if you've a bit of charm about you, +60 often suffices and +80 should really see no quibble. Anything more and unless she's offering some truly prime qualities you're being fleeced. Be aware some of these ladies, particularly the trafficked ones may be lax in the use of protection or may be being used unprotected by controllers as well as punters who stealth or blatantly insist on going raw (against the SPs wishes). So watch out for warts, herpes, discharge and odour before you tuck in.
Also don't forget that both Chinese and Thai are opportunists so they may well quote high, the youngsters and the deluded may insist on 100+ for extras, just see someone else, don't get into protracted negotiations just politely decline acknowledging to them they have their price which is too rich for your blood, especially if you're on a budget. If they acquiesce to more than 20 off their opener then you'll of course have to be wary of poorer service or restricted access, not always but likely. The Thais, per their culture, are usually more good natured but the Chinese aren't always gruff, in either case play it civil with some pinches of cheekiness and things will proceed as smoothly as they were ever going to.
Assuming they haven't blatantly grabbed your bare cock or slapped your arse with a playful scolding at the start you could make your first invitation to treat using a pitifully small (folded) towel over your bare-faced cheeks to greet their entry. Resting your elbows and hands near the edges of the massage platform is enough of an invite for the "courtship" to begin. The jobbing veterans may be more pleasant as they open massage proceedings with their unsubtle pressing of their pubises, bellies and boobs against you and a reciprocal tentative caress of their calf should pretty much confirm if the horses are in the gate. Once the games afoot you can tease out the massage and see if you get CCs and RUs to suss out how sensual they're inclined to be or you may have a girl horny enough to get straight into the scrimmage who may well sit on your face for a good 40 mins if allowed.
Hopefully most of the above was teaching you to suck eggs but do be mindful and enjoy.