It is a common misconception that multitasking is this art of doing more than one task simultaneously. Of course, in reality, multitasking at work is not doing multiple things at the same time, but sharing bursts of time between two or more tasks in an age where we are constantly interrupted.
But sometimes multitasking can be an ineffective waste of time - why is this? Multitasking is a delicate blend of organization, prioritizing and balance, not just trying to do everything at once. Trying to do too much at the same time can lead to multiple unfinished or poorly completed jobs.
The key to effective multitasking is working on only one task requiring complicated thought processes and decision making, and keeping the others basic or mundane. Say, switching between writing a report and buying stationery online.
Pair up tasks which cover each end of the spectrum. Switching between two complicated tasks can leave you with a confused and unfinished mess. Having one complex task interspersed with a simple one can give your brain the rest it needs, while still utilizing that time effectively.
Make a guesstimate of how long your daily tasks will take you. Do any short tasks on their own, as this will be best use of your time. Work two longer tasks together so that you don't get so distracted, for example when you get sick of writing your 10 page report, catch up on your filing, and then switch back again when you're bored.
Next time you start trying to do everything at once, take a second to think about what task works well with another and you'll end up with a much better result.
Ref: Business Forward Issue 53