First, you
can start directly at the sofa in the Strip Club but that will limit your possible points. It is still possible to succeed on this path but there are other ways. If you start at the Bar instead, you have the chance to interact with Candy and build your Reputation points. Rep points are scores that affect everyone. You can see those by noticing the scores for the girls you have not yet met. If you maximized Rep points at the Office in the morning, you will be at 3 - with Emily at anything between 3 and 10, which doesn't really matter here, and the score for characters you haven't met at 3. If you go straight to the sofa, that is where you start. By going first to the Bar you can get that up to 6, which affects everyone including Azumi and Natalie.
Any time the game panel picture is surrounded by a red border, it means there is at least one (or more) hidden hot-spot. Look for alternatives to the action choices shown at the bottom. Some will offer "free" points. An example is when Natalie first comes into the private dance room, Azumi turns to her in a panic. On some (not all) paths, you can admire her butt and earn an extra Azumi point. There are a number of these "free point" chances throughout the game.
The girls react well when you admire them or show interest. In the office, you get Emily points when you admire her legs, notice her breasts under the tight blouse and so on. The same goes for Azumi and Natalie. In addition, Azumi reacts with interest when you notice her abilities. If you tell her you were faking when you passed out or ask her how she is "doing that," you will get some points. She also is interested if you comment on her relationship with Nat. Groping her when she helps you out to the cab will earn 2 points. The same with Natalie. Tell her you want something more to happen and you'll earn points with her. Give her a hug when she is on your lap and about to go back out to dance, leaving you with Candy, for another one.
Basically, treat the girls like people you like and not hot bodies you want to score with and they will react well. That helps build points. Help them when problems arise and you will earn more points.
A good average rule of thumb would have your scores after Azumi's private dance but before you fake falling over at N=5 A=6. When leaving the club for the Taxi, a good start would be N=9 or 10 and A=14 or 15. Keep earning points during the cab ride but beware. In that scene, not every "higher" point option is necessarily the "best" path. In some cases, paths that cause one or the other of the girls' points to go down might be a better way to go.