Start to office 20 minutes earlier that you do to reach on time. While you need not be in the office 20 mins earlier, it gives you extra time to relax at the office, stretch out and listen to music to refresh your mind.
Other benefits like compensating for the loss of time due to traffic snarls or snafus at home or on the way will not delay you and put you under the wrath of your boss. Better yet, you will no longer be penalized for the delays, since there won't be any.
Arrive on time, or starting work on time means you won't have to scurry through the first few minutes to make your life easier.
Do something creative in the 20 minutes that you have at the office when you arrive early.