Celestine Chua at Stepcase Lifehack (http://celestinechua.com/blog) writes a good article dealing on successful Time management hints (full article at http://www.lifehack.org/articles/lifehack/20-quick-tips-for-better-time-management.htm).

What follow are my comments:

1. Create a daily plan. True, but leave you a little flexibility in order to deal with unexpected  requests. Managing time doesn’t necessarily mean havin no contingency at all.
2. Peg a time limit to each task. Ok on this, but it assumes you can have a correct estimate on time needed.
3. Use a calendar. I agree is fundamental, but for a successfull use you need also other people use it (means that if you have people not updating/using the calendar, is not so effective to have it on your own…and yes! exist people at all levels that refuse to use a calendar)
4. Use an organizer. Be sure to use an electronic one only if you’re confident in using it, otherwise a plain good old paper one is still ok
5. Know your deadlines. And accept less those giving you too much or concurrent due dates
6. Learn to say “No”. But evaluate to who you’re saying no: is sad but saying no to colleagues is easier than saying it to your CEO
7. Target to be early. Challenging but achievable due dates are a good way of getting things done in time 
8. Time box your activities. Is desirable, but depands a loto on the kind of work and level of responsibility you have.
9. Have a clock visibly placed before you. A true one, not a digital one, because gives immediate perception of passing time.
10. Set reminders 15 minutes before. And try to avoid using “snooze” button.
11. Focus. The elephant is eaten one spoon at a time, and so do activities.
12. Block out distractions. Work is an exclusive activity, so don’t try to chat or do other things.
13. Track your time spent. True! I’m surprised how often people avoid tracking what they do.
14. Don’t fuss about unimportant details. This is quite tricky, since I prefer a good content in time, other than having non-perfect content late, but there are persons that want to release things the nearest to perfection they can, despite time taken (but of course tehy don’t pay for them )
15. Prioritize. True. This is the real key.
16. Delegate. And remember to have time scheduld for checking the work at different levels.
17. Batch similar tasks together. This is true but I think can change form person to person.
18. Eliminate your time wasters. I agree on this, but is very linked to you attitude towards work
19. Cut off when you need to. This is also a sign of your ability to manage time. 
20. Leave buffer time in-between. Cool off and then go ahead.

Note: As usually I tried to leave my comments on Stepcase Lifehack, but got deleted. They did not seem so offensive neither to Celestine nor to Stepcase. I would like to think is a tech problem….