So, I've tried this game a few times before, but always hit a bit of a wall after a certain point. Can anyone give me some advice about how to make progress in breaking out of the cycle of "win a bunch of the easy fights, make a few home improvements, get Juno and then fail endless rolls?" I really enjoy this game, but I'm clearly not following a good strategy here. That, or I'm missing something.
If you're starting with low charm and/or manipulation the key to making progress with the girls is to first take them along with you on combat missions until their respect for you is very high. Make sure to pick up some armor for her and give her a weapon. You can take them back later and give those to the next slave. She won't kill much but you don't want her to be a damage sponge either.
You will see a message at the end of combat saying something like Juno gains respect. The first time you don't see that message her respect is maxed out. Respect acts sort of like affection making most of the things you want to do with her easier. So even with low stats, at very high respect you'll start succeeding with some of your charm and manipulation checks.
First, you want to focus on charm actions with her because those raise happiness and affection when you succeed. Manipulation is for reducing her willpower but it makes her unhappy and reduces her affection so don't do that until she really likes you. You can also do events with them at night to boost happiness and affection like going for walks, going to the theater, going to dinner/etc.
Once you get to where you can succeed at passionate seduction attempts, sweet talk her a couple of times til her arousal goes up, then spam kissing and caressing until the foreplay time is up. When that happens, suggest sex. Do the normal option first since that doesn't piss her off. Either do blowjobs or vaginal sex and always start with nicest version whether that's careful/normal/passionate. She probably won't like it at first unless you took pussy pleaser and/or arouser so she might beg you to stop. Stop if she does. She'll still gain some affinity for oral or vaginal sex which means she'll be more aroused by it the next time. If you're ending those sessions with negative arousal you're wasting your time. Her affection/respect/happiness is not high enough yet.
Do oral and vaginal sex with her a bunch of times and that will raise her happiness and affection for you to pretty much max. That's when you can start being dominant, critical, etc to start lowering willpower. You can also use bondage to lower willpower but you really want to get her happiness and affection up to high levels and you also want to get her to where she enjoys oral and/or vaginal sex. Save anal for later that's harder to get her to like.
An easy way to lower willpower later on is to turn her heal option on and criticize her when she does it and also be dominant about demanding she shower with you. The heal option doesn't always work. The shower is more reliable but she gets mad at you so you have to fix that later.
Edit: Also just figured out from testing that aggressive petting is an easy way to raise bondage skill. Haven't figured out how to raise flagellation yet.