Hi Spring,
You've already figured out that triggers are very particular to an individual, and that's a good beginning. You may know the "bucket" metaphor for mast cell disorder patients. We can be exposed to small amounts of triggers and not react. These exposures fill our "trigger bucket," and, if the bucket is full, one small exposure to a trigger can cause it to "overflow," triggering a reaction.
As you know, these reactions are not true IgE allergic reactions. The triggers are triggering the mast cells to degranulate and to dump a variety of mediators into our bodies.
Some foods are triggers because they cause direct histamine release from the mast cells, but other foods actually contain high levels of histamine. Because your "bucket" might be more or less full on any given day, you might or might not notice a reaction. For example, on a good day, I can eat chocolate, but on other days, it'll cause me problems.
This link lists the top 10 histamine containing foods. The one thing they left out, possibly because it's impossible to determine the actual amount, is leftover meat and fish. As soon as they cool, bacteria begin to produce histamine in them, and after even a few hours, they can cause problems. Freezing leftovers shortly after cooking, keeps this process from progressing.
http://www.reverta.com/blog/histamine/top-10-histamine-containing-foods/