Most people who wake up at 4 a.m. do it because they have to—farmers, flight attendants, currency traders and postal workers. Others rise before dawn because they want to.

Russ Perry, the 33-year-old Scottsdale, Ariz., resident and founder of graphic design firm Design Pickle, says that 4 a.m. to 6 a.m. is “the most planned, most organized and most scheduled part of my day. It’s a crapshoot from there.”

Once...