"I can talk on this subject with authority, because I used to be the most disorganised person!" admits Dr Marilyn Paul, author of a new book "Why am I so disorganised?". "From major examples of chaos, down to never putting things back when I'd finished with them, I had so many bad habits."

But if you want to achieve true work–life balance, you have to be in control of how you spend your time, and put in place new, better habits. "It's all about changing your mindset," she adds. "Just like dieting or giving up smoking, organising your life is not a set of tips, but a new approach, with new habits to learn and practise until they become second nature."

Clearing your desk and writing a "To Do" list is not enough, she says: in two days you've lost your list in the clutter, and you're no further forward. You need to start by understanding the depth of the problem, and building your motivation to change.

Ask yourself:

• What do you really want?
• What is your disorganisation costing you?
• How will you benefit from the change?

Just like athletes visualising breaking the winning tape, you must visualise the person you'd like to be. "Fix on ideal images of yourself at work – smart, calm, professional, with everything under control – and keep them firmly in mind," says Dr Paul.

Next, take an honest look at the true cost of your lack of organisation – quite apart from the horror of living in chaos. "Many people I have counselled in organisations over the years can say they have lost perhaps £10,000 or £20,000 by missing out on promotions, productivity bonuses, or pay rises.

"Being unreliable, producing messy work, missing deadlines, skidding into meetings unprepared, and never being on time will ultimately mean that you can't make the career moves you'd like to," explains Dr Paul, a specialist in change management. "If you're a disaster area at work, you simply won't get promoted."

Dr Paul explains also that your work-mates secretly loathe your behaviour. "You make life harder for them too, as they have to pick up the pieces from your lateness and lack of preparation."

The final preparatory step on the road to an organised worklife, is the toughest. "Take responsibility for your part in the chaos! It's no good blaming your boss for giving you too much work, for example. You need to learn ways to say no, to get help, etc. It's up to you to change that situation."

So, armed with your visualisation, your motivation and your understanding of your own role in it, you can move forward. "Only then can you start re-organising your desk and your work methods," Dr Paul says. "Plenty of great techniques, strategies and products exist to help you sort yourself out, which I explain in my book, but you have to understand the benefits to you and those around you, and really want to make a change."

In her 25 years working with firms such as Motorola, Pfizer and the New York Times, Dr Paul has witnessed many people with excellent skills being hampered by disorganised behaviour. "I've seen a terrific social worker who constantly failed to get his case work in on time, so couldn't rise above Supervisor; a pharmaceutical executive who clung onto documents and had huge piles of papers covering the office floor; and a professor who couldn't keep on top of lecture notes, course work and marking student papers, and who lived in a constant agony of chaos."

Being disorganised, she maintains, is an expensive luxury. "Do you really want to be permanently stressed and overwhelmed, living a hectic and frenzied lifestyle?" she asks. "Believe me, there is an easier way!"