Typically, I run through lists like to-dos for companies/projects, the day's agenda, topics/ideas, recollection of the previous day, reflection on mental and emotional state.

Some days are more structured than others, and I don't try to conform too tightly to any particular structure. The goal is to get my brain outputting something, and later in my morning I'll transform or rewrite whatever I spit out. During very busy or demanding periods this also ends up functioning as my primary daily journal entry.