If you work in a big bank, broker, exchange or software vendor, you will recognize the relentless tsunami of email, phone calls, customer visits, conferences, project meetings, town halls and other "mandatory" appointments that continually fill up your calendar.

They all seem really important and urgent at the time, but do you ever take a look back over the last month or year and ask yourself whether they really were that important in the big scheme of things? Did they improve your career or take your business to the next level? Did they save you from some disaster? Or did they just evaporate into thin air?

When my company turned two recently, I took the time to look back and think about what has worked and what hasn't. When compared to previous jobs in major companies, the single biggest difference I've noticed is one of dramatic productivity gains. I'm not talking about a 25% or even 50% improvement, I'm talking about one person being able to achieve more than an entire team in past roles. How?

I believe the secret lies in "switching" - the mental effort associated with changing topics in your brain. The less you switch, the more you are focused on one task, and the more productive you become.

Ever felt that frustration when you are making headway on a document only to have the phone ring or email arrive that grabs your attention, and then you find it difficult to finish the document? That's switching. It's losing your train of thought. It's distraction. It's inefficiency.

But wait I hear you cry - I can't control when these meetings happen, or when the phone rings, or when the email arrives or... You are right, and it is unrealistic to suggest that everybody can eliminate distraction completely. But even small steps can boost productivity by avoiding switching costs though, so here are seven suggestions to get you started:

1. Turn off email for large chunks of the day. Some people have begun to treat email like chat for some reason, sending rapid-fire one-liners. Email is not chat. Assume that anything that arrives by email can wait for a couple of hours for a reply. Turn on your email a couple of times a day when you are ready to focus on it exclusively.
2. Have a notepad on your desk, and jot down phone calls or other things to do. No matter how good your memory, trying to remember lots of tasks will always distract you from your primary task. Write it down and remove it from your brain.
3. If the phone rings and it's not urgent, quickly tell them that you'll call back, write it on your paper from tip 2, and turn your full attention back to your previous task. Always make sure you do call them back later in the day - the goal here is to be productive, not rude!
4. Never attempt to "multi-task". The fact is that you are giving multiple things only part of your attention and switching costs are off the scale. Unless you can accept low quality results, don't do it.
5. Try to cluster meetings together in the day to create large windows of uninterrupted work time. You will find that three hours of meetings back-to-back in the morning will create a far more productive day overall than when those meetings are spread out across the day.
6. Say no to meetings when you don't actually think you are required. (Easy to forget this one!)
7. And finally the ultimate productivity booster - leave the office. Take your laptop and go somewhere you won't be disturbed. Lots of people try to work in coffee shops which can also be loud and unproductive. Some people can work effectively there, but if you are like me, then seek out quieter places like libraries, museums or parks.

For more on this topic, I'd recommend reading Rework by Jason Fried and David Hansson. I hope this list helps you to become more productive. Feel free to comment and tell me about your experiences or suggest other productivity tips that have worked for you.