Hmm...I never tied a girl that I ever tickled....if anything, I may have wrapped my arm around the ankles of a few of them while tickling their soles with the fingers of my free hand, but even then, it was rather brief...a mere tickle aesthetic, if you will...for that matter, I was never tied myself...frankly, whenever a lady went to tickle my feet, I was very naturally receptive and accepting of it...many were the times I'd offer girlfriends in my past (and, even a few good female friends!) my bare feet...from which, they'd go to town and tickle them until I was senseless!! 😀 I've heard accounts that tying can actually intensify the sensations; what with any movement now limited...but, I never found it necessary to do, or have done.
As it is, I prefer being able to tickle BOTH feet simultaneously...if the lady in question needs a moment of repose, she can obtain it fairly easily...more often than not, the lady in question would freely put her feet back to allow more tickling!! 😉
Naturally, when it comes to tying/bondage...it takes trust....a WHOLE lot of it...