Seaweed and/or kelp extracts, any I can get a hold of. Humic acid. During veg, try making a tea of alfalfa hay (good quality) or meal, just put a handful of hay into a liter or gallon of warm water, let it sit an hour, strain and foliar. It's chock FULL of a nifty little hormone called triacontanol. For that reason, don't use during late flowering.
Calcium/magnesium supplements are great to apply as a foliar IF necessary (otherwise I top-dress dolomitic lime), as are teas made with things like worm castings (the vermi-tea you mention).
Botanicare's Maxsea I am liking more and more, especially in a foliar application.