The most overlooked time management technique, I think, is taking care of yourself first. By that I mean, make sure YOU are ready to work at your best. This is accomplished by starting your workday rested, refreshed, and with food in your belly. To be blunter, it is a requirement to get enough sleep, proper nutrition, a little exercise, and some downtime away from work. When you are mentally fit and ready to work, you can concentrate and perform at a higher level.
Another tip that is overlooked is having a clutter-free environment. Excess "stuff" in our work area tends to boggle our minds, making it hard to concentrate. Put items in folders (physically or on the computer), or the very least stack all the files for specific projects in their own piles and set them out of your direct view. Then your mind will be more likely to stay focused on the task at hand.
Being able to concentrate in a clean environment enables one to make decisions easier and be more productive and hence get more done in less time. That alone makes it worth the trouble!
Another way to get more done is not to do it! I am referring to delegating tasks that others can do more efficiently; or perhaps tasks that don’t really need to be done. There are likely items on your "to do" list that would make little or no difference if they were ever done. Don’t clog your in basket (or in box) with them in the first place. Just delete and move on. This is can be a quite freeing strategy.
Now, for actually managing the time you have set aside to work, I have two suggestions. The first is a "hard" calendar, the one with your appointments. Then you need a "soft" calendar which is like a "to do" list, but you have your higher priority tasks blocked out for specific times. (Just like you would a real appointment, but it is an appointment with yourself.)
If you have a big project to do, you can divide it into smaller tasks to work on during the "blocked time" or you can just start. Sometimes just starting is the biggest problem of all. Doing the same work over and over causes us to lose focus, so it helps if we set aside a specific amount of time. We need to change our mindset to one of progress not completion. Over time, even a seemingly insurmountable goal can be accomplished if you keep with it.
Another tip that seems to help is to "batch" the same sorts of tasks together. For instance: making phone calls, data entry, or answering emails. More difficult tasks like writing or reading might require a break every once in a while, in order to maintain focus.
If you have appointments or networking lunches out of the office, try to schedule your “out of the office” appointments on the same days (just not too close together timewise.) This tactic saves you travel time and the "readjustment period" when you get back to the office and try to settle in and get back to work.
Avoiding distractions whether you work at home or at an office can be handled by having specific hours that your staff or family knows you are not available except for an emergency. Save this sacred time for your most difficult and complex work.
Most of us tend to do our emails and easier work first thing in the morning, but we are in effect wasting our best and most productive time on minutiae. Instead it is more productive to do your big, complex, important task first. Answering someone else’s email is not your first priority – getting your work done is!
You can also try setting little mini goals within your workday, like see how fast you can get a certain task finished or how many smaller tasks can you get done in 30 minutes. Best to save those sorts of tasks till the end of the day, or at least in the afternoon. That might even be an incentive to get those last few things done before you quit work for the day.
Set up a schedule for bigger projects and write it down. This gets your subconscious ready to do the task, even if it is weeks or months down the road. You will find that you have collected a myriad of helpful information needed just because you set your intention.