Use Pomodoro - 25 min work, 5 min break, 5 min context switching
8 hrs = 13 poms; 1 pom for lunch; 5 poms for helping others. So 6 poms for work
set micro goals for each pom - keep writing what you are doing in the current pom
Master the interruptions - externalize your current context by taking good notes. This makes it easy to stop a pom at 25 min sharp and deal with interruptions (only critical ones)