I went through some of your previous posts to give you ideas similar to what you had written but I came up blank. In doing so I stumbled upon a request you made 3 years ago and started drawing up ideas to fulfill it but I think I talked myself out of starting a stand alone series. So I'll just put that idea here:
I was thinking of having a girl of some age writing a tickle-fiction somewhere public. A (someone she knows, classmate or co worker) catches her and tries to see what she's writing but the first is really secretive about it, clutching it to her breasts or whatever. Second girl leaves and after some time, through some means I hadn't gotten to, the first girl is transported into her fiction, essentially living out her tickle-fantasies. The first girl, who I had initially written up as snobby and self centered (early draft) returns at some point in time and discovers the writing lying there and is also transported in (some several days after the first girl, so there were several days where the first girl went through tickle-adventures). First girl figures out what is going on pretty quickly because she wrote the thing. It's just a series of encountering tickle-obsessed monsters, which employ tickling in unique ways that are impractical and don't make a lot of sense. I had the idea that these creatures were all about tickling young damsels but the two would never really encounter any other women. For a long time it's just the first girl getting tickled with the latter being ignored, which creates a sort of foil between the two. Eventually the second starts getting tickled too, initially despising it but growing to enjoy her time in the fiction world. Second would complain a lot early on while the first would be having fun and then that would slowly reverse, with the second wanting to continue adventuring and the first wanting to go home. I had a few plot ideas like the first girl continuing the writing while they're in the world (undecided) and another where they have to follow a pretty linear path because the world around said path doesn't exist. I had thought that near the end the first would escape while the second would remain, possibly ending with the second girl never actually existing, albeit a weak twist. I also had thought about there being some dialogue after the second girl figures out that the first created this world, or that she is continuing it. They're adventuring towards the end and can't really avoid the tickle-monsters, not that the first wants to. There might be some more details but I've forgotten them.
I had planned on using a group of witches (employing something I was going to take from another story I had written), skeleton-pirates (they fix the one girl to the bow), mermaids (girl falls off the bow or is forced to walk the plank, mermaids picking at feet, unusual), werewolfs (licking), and ghosts (something about activating nerve endings without touch).
I intended for each 'chapter' to be fairly short and to just do a bunch, eventually showing some arcs with the characters. Im flip flopping on the idea and the amount of work it is because I dont have any spare time at the moment, so maybe I will maybe I won't, but the idea is up there for you. Im also considering just employing a lot of the ideas into another series that I started and never finished, because I kind of wanted to explore those characters some more. Ill probably do the latter.
I also had some idea a few years ago about a elf (the race of elves are more ticklish than humans because magic) being tickled for a code word of sorts to enter some place, but the elf doesn't speak the common tongue and doesn't understand what they're asking for.
Cheers.