I am a massage therapist, so I might have some tips. I often have people tell me that their feet are too ticklish to be massaged, but in the 5+ years I've been doing massage I've only had 1 person where that was actually the case.
What works for me is if someone is feeling ticklish to slow down the strokes and use a firmer pressure. 99% of the time that will work. If they are still feeling ticklish have them take some deeps breaths along with the firmer pressure because anxiety will make some people feel more ticklish and deeps breaths will help them to relax