Kaito 1412, I've got to admit to not really understanding the second part of your post.
Well, probably the best example would be the
Jisei series from sakevisual, in particular
Kansei. By outward appearances of the house, there doesn't seem to be any suspicious objects lying around. However, investigating the boxes in the basement reveals documents pertaining to some of the victim's previous work, investigating a cabinet after we learn about it being in a blindspot in the cameras enables us to crack open the cabinet, and completing that reveals a second lock that needs a key and supplies a cryptic description of the hiding place, which in turn allows Kangai to notice a second blindspot in a different part of the house if we investigate the hiding spot. Furthermore, going back to my first point, Kangai can only unlock either the key or the documents, not both, depending on what he chooses to do when they need to override the office door's security. Additionally, there are five endings, all of which are based upon both the previously mentioned choice, as well as how he interacts with each suspect: if he's less than truthful with Sophia after choosing to reset the power himself, Sophia will confront the killer herself with the critical evidence; if he instead levels with her after making the same choice, she'll give him the critical evidence and allow him to identify the killer himself. Though it's the same killer every time and much of the actions overlap, the story isn't really linear, the background forces players to be more imaginative, and it gauges relationships. If it wasn't so heavy on witness testimony, placed more value in physical evidence, and also allowed players to use evidence by choice (rather than making it automatic), it'd be the perfect model -
Jisei in particular suffered for these choices.
However, for how to handle the choices,
Ace Attorney isn't a bad example either. Frequently, the player is forced to justify its choices, clarify what about our choices creates contradictions, balances the importance of evidence and testimony wonderfully, and even left plenty of red herrings (and Logic Chess from AAI2 is the perfect example of how to approach testimonial matters like my example from my first point). However, even this franchise has fallen flat here occasionally; the first example that sticks out is the game skipping over whether or not Moe failing to see white roses was important. Additionally, we can see fabric sticking out of a muffler or a shift in the paint on the floor if we're observant enough, so whether or not these locations are worth investigating is based on what we see. In my opinion, a purely verbal CYOA should be more heavily based on how deeply and imaginatively we're willing to think, and the details are only revealed if we choose to investigate more closely as is done with the
Jisei series. Finally, and most critically,
Ace Attorney is linear. Doesn't matter how many times we screw up, we still get the same information and the end results, we just have to double back more often if we make a wrong choice. There have been some bad endings, but these only pertain to single cases. The rest all progress the same way, and no amount of apparent incompetence is going to change the sequence of events.
Overall, I say blend sakevisual's use of unassuming backgrounds, relationship meters (though their meters are concealed, but this is ultimately to your discretion), and love of alternate endings with the
Ace Attorney method of presenting evidence by choice, defending its importance, and constant red herrings - possibly even allow the player to build a strong case against the wrong suspect.
Doing this requires threads to become shorter. Less description until we ask for it, less answers unless we ponder the possibilities, and more need to defend one's choices. Short, straightforward, and no embellishments unless they ask for it. This is what my second point means.