You can also just keep asking them to do something that you know they will reject. Then keep replying "maybe later" for a lot of easy love points. Ask them to do everything once every part of the day, so they don't get annoyed with you. Usually the titjob, handjob, footjob, and blowjob options... you can ask one of the girls to give you a blowjob and they will usually turn down the idea, then chose the middle option of "begging / please"... a lot of times they will say "can I give you a handjob instead?", accept it then do some off hand action with them or just keep pressing continue until they get slightly aroused, then chose the shift action option to get the blowjob or titjob that you wanted. Which gives you easy amount of inhibition and obedience.
Also whenever possible get them a dildo and gift it to them. I believe it gives an easy +40 of every state. Though they get kind of annoying since the girls will always pull out a dildo and masturbate while you're having sex. So if you don't want them to constantly use a Vibrator or Dildo to show you how woefully inadequate you are, then don't give it to them.