I might try to write something more thorough later, but the basic idea is to try to have a lot of both good and bad points. You need to pick up the sexy outfit
after the beach trip at its LATEST (you need 10 bad points for this), this is so you can get the whore outfit early (you will need 30 bad points) which lets you get the bimbo transformation without needing to tank your good points (which would be difficult and get in the way of some of the Dad route stuff, you need 25 good points to get pregnant).
Edit: Alright so I tested it and the route is possible, but it is kinda buggy, for a lot of scenes Ashley's images revert from "bimbo Ashley" to "good Ashley", guessing EvaKiss didn't expect this to be possible or something.
The route is a bit tight, try to avoid too many choices that lose either good or bad points, but you will also need a lot of both points so early on you need to keep as many routes open as possible, I stopped Eva from becoming a slut early on and kept an open relationship with Eric (also avoided anything that triggered the "cheated on eric" switch and didn't make him a cuck), you can farm a lot of good points from those 2, to get bad points you need to be a bit of a slut, do the blackmail scenes with Wilson, go on dates and sleep with Jack after the beach trip, post a lot of slutty pictures, do Tyrone's videoclip and sleep with him, etc.
You need 10 bad points after the beach trip to be able to pick up the sexy outfit, then you need 15 good points to have sex with Dad, and then 20 to accept a relationship with him, keep building bad points so you have 30 to get the Whore outfit after getting the boobjob, choose to stay living with Dad, and then make sure you still have 25 good points in the late game so you can choose to get pregnant with his child.
Edit2: Realized you don't need to get the sexy outfit after the beach trip, you can get it a bit after refusing to be in Wilson's gang, you just need 15+ bad points, this is good because this way you can still do the Ryan route (getting the sexy outfit too early locks you from it).
Edit3: Feel free to try to modify this route if you can, but here's a possible walkthrough for being Dad's bimbo.
You can afford to get more tattoos and piercings than I did, do keep in mind you need at least 1 money to turn into a bimbo. Feel free to try to get different events or whatever, just keep in mind the point requirements to progress the Dad route and get the outfits.