Please make sure to ask before you tickle people. Be aware of the common form of initiating tickling that leaves the person who would be tickled with no way to say no:
“Are you ticklish?”
“Well, let’s just see then.”
In my experience, adding “I don’t like to be tickled” is usually ignored. This is especially common when there are more than two people present, as the person who is tickled is usually held down by one person and tickled by another. I hope you realise that if you feel this is necessary, you are probably violating someone’s consent.
Remember, laughing and smiling whilst being tickled are involuntary responses. Listen to what the person who might be tickled says before and during tickling.
Now you know how to have tickling that is fun for everyone involved. Yay!