1) I think all long-term punters have gone through a fluffy stage at some point. Wish I had known that it's not necessary.
2) Not to fall for a girl, who, after all is only interested in your money.
3 )Attitude and service are the key. Age, body type (within reason), ethnicity, etc etc. are secondary.
4) Stunning girls rarely provide the best service - they think that their looks are all they need. Lapdancers usually make shit prostitutes.
5) Don't be shy - if the girl advertises, for example anal, confirm before handing over the dosh that you will, in fact, be able to do her up the arse.
6) Don't be afraid to walk if any of your punter instincts tell you to.
7) Let your big head do the thinking and your little head do the shagging.
8) There's plenty of girls out there (at least in London) so don't jump through loads of hoops to see any one particular girl. If they don't show a phone number, move on.
9) Avoid elite courtesans like the fucking plague.
10) THERE IS NO CORRELATION BETWEEN PRICE CHARGED AND SERVICES RECEIVED. NONE AT ALL.
However, if you see a girl charging below, at present, about £90/hr, the chances of the girl being pimped, conveyor belt, bait-and-switched, etc will be far greater.
That's what I wish I'd known over 30 years ago, when I first started. Hope my advice is helpful.