I am a big fan of lists. I make a to-do list every night before bed & I try to prioritize it. I find that after a few hours I start to suffer from brain fatigue, so I take a break for 30 - 60 minutes and do yoga, play a game, or do something creative. I find that it pumps me back up to work. I also have a playlist of inspirational and motivational music that works wonders.