I did a quick search for threads like this but didn't see any particular one that stood out.
It's simple, I will say a word/name/short phrase, and the next poster follows up with whatever word/name/short phrase comes to mind.
For example, if I say "peanut butter," the next poster might say "jelly" or "crackers" or "crunchy"
There's really no "guideline" to what should be said, just whatever you feel like.
And if this is a repost, just let me know and I'll go there to continue it.