Since I want my trinkets to actually be available when I need them, I have elemental mastery, blood fury, and both trinkets on a single macro. For boss fights my rotation goes:

Hit 4x flameshock key
Hit 4x Lava Burst-only key
hit my trinket/ele mastery macro
hit my bloodlust macro (probably should combine these)

Spam my castrandom macro until end of fight or whenever flameshock needs refreshing.