I commend you on wanting to write a (M/F?) tickle story.
I would suggest writing about your fantasy/dream.
There are enough people here of like mind, I'm sure.
How about the classic Asylum where a sane Women is imprisoned and has to go trough daily tickle sessions on her feet, breasts and armpits. Add some sadistic Nurses and it’s perfect
I had thought more about something like a series. Something like: Flash f / f, Vampiric Chronicles f / f, Sons of anarchy, One piece f / f or something like that.
But any suggestion is welcome, thanks for the suggestions DarkGug