Some ways to get in gear:
Write down your to-do list, then check off each item as you go for extra encouragement.
Break big tasks into small chunks. Tell yourself you'll just write the opening page of that report or clean out that first file drawer. Then take a short break before starting again -- or seize the momentum and plow straight through.
Get a pep talk. If you're behind schedule and feeling overwhelmed, ask someone close to you to cheer you on at every small accomplishment. Offer to be her cheerleader next time.
Reward yourself. You'd give your child a treat if he did a tough job well; why should you be different? Try to tie the goody to the achievement: Finishing that memo might earn you a special coffee drink.