Clarity of mind - Prioritising what to do & knowing what not to do is the beginning of efficiency.
Setting a deadline - Giving yourself a deadline makes sure that you finish work in time.
Getting rid of distractions - An environment where you can focus without being distracted helps a lot.
Keeping yourself healthy - A healthy mind & body is capable of performing at peak for a longer time.
Awarding yourself - Giving yourself a treat after you finish your work motivates you to do more.
Letting yourself rest - A good sleep, a nap or short breaks keeps one stress free & energised.
Determination - One who is determined becomes proficient in his work day by day.