Clearly, though, many of us are not working smart, but - and there's no easy way to put this - stupid. British productivity remains low while the number of hours we work exceeds that of some of our European neighbours. One result of this is the dismal array of statistics set out by the Mental Health Foundation: when working long hours 27% of employees feel depressed, 34% feel anxious and 58% feel irritable.
4. Leave work at work
Imagine you're just about to leave your workplace, possibly for cocktails at TGI Fridays, even though it's actually Tuesday. Before you do, write a note to yourself listing outstanding tasks or any work things that are on your mind. "Then shut the diary, turn off your PC, store your message and leave it." counsels Allen. "Focus on the image of shutting the diary, saving the message or turning off your PC." If this is not possible, she recommends what she calls a stop-breathe technique. What does that mean? "Take a slow breath and acknowledge that you've left. If you can't do that at the office door, when you're getting a train or bus and the door closes, imagine that's the end of your working day. Or if you're in your car, sit at the wheel for a short while before you start the engine."
Closure is a big theme among those offering tips to a healthy work-life balance: the Mental Health Foundation says that if you do happen to take work home with you, you should try to confine it to a certain area of your home - and be able to close the door on it.5. Forget about perfectionThe injunction to put work away for the day sounds fine, but hold on. It's surely not as simple as that. As you leave work, you realise you haven't done something as well as you could. You turn on your heel and go back to do it right. Is that so very wrong? "Well," says Allen, "some people find it very hard to let things go. I call it 'good enough versus fabulous'. Sometimes, if you're overworked, you need to explicitly tell yourself that what you've done may not be perfect, but it is good enough." She cites the example of a woman who goes back to full-time work and finds that her partner doesn't do the laundry as well as she used to; he just piles mangled T-shirts with their sleeves still inside out on the radiators. "But she has to let that go because the alternative is she takes on more work when she's already stressed out. What I'm saying is, don't put extra pressure on yourself when you don't need to - at work or at home." As Netmums tells working mothers in its top 10 tips for work-life balance: "Give yourself a break. It doesn't matter if your home's not immaculate and your children aren't fed super-nutritious, cooked-from-scratch food every day."6. Don't be a martyr"There is also the tendency I come across where somebody will say, 'I have to do everything round here,'" says Allen. "To feel like a martyr gives some people a great deal of pleasure - they feel they're powerful and busy." And what's wrong with that? "It's worth thinking about how infuriating that is for other people. The reason most people are martyrs is that they want the approval of others; if they realise martyrdom - just doing all the work - is exasperating to be around, they might stop behaving that way."7. Ease off the adrenalineDo you need the rush of adrenaline all the time, whether it's at the gym, in the sack or at the coalface of paid employment? "You really ought to monitor that," says Allen. "You need to ask yourself how well your life is really going. What happens often is that those hooked on adrenaline hop from one rush to another - from one task to another, from work to gym. What's that like for your family and friends to be around? Not much fun, especially when you crash - which inevitably you will."
8. Think about retirement"Some people are wedded to work, especially if they're self-employed," says Allen. "But I get them to ask themselves: if work is the only thing you do, then what happens if you lose your job or if your business fails? I don't underestimate the difficulties of putting work back in its box at a time of austerity, but I try to encourage my clients to think of it this way: for most people there will be gaps in employment. What do you do then? And what about when you retire? Sure, you may well carry on working in a part-time capacity, which I think is a good thing, but you will need other interests in life when work becomes less important."
Is she talking about hobbies? Stamp collecting, perhaps? "No, that does sound old-fashioned. But we all need interests we can fall back on. We all need something we can fall back on that isn't work." The Mental Health Foundation reckons that overworked people should try to reduce stress through exercise, relaxation or hobbies. Throwing darts at a picture of your boss is a satisfying way of cultivating all three de-stressors at once.
9. Make 'em wait
One way to avoid being incessantly available is to make it clear to your colleagues that you will reply to emails within 24 or 48 hours. "As long as you're reliable about replying in the end, it's surprising how little this bothers people," argues Oliver Burkeman, author of Help! How to Become Slightly Happier and Get a Bit More Done. Quite so, but texting is based on different parameters - to send a text is to expect a quick, even immediate reply. But fear not, remember point two - just say no. You need to make it clear that you're not endlessly available for work queries outside working hours. Admittedly, that's easier said than done.
10. Set your own rules
"You really need to find your own work-life balance, probably with the help of others," says Allen. "The important thing is to ignore the shoulds - the shoulds that comes from other people or from you internalising others' mindsets. You have to rely on your own intuition."
We are witnessing a generational shift in our attitudes to work. Millennials (those born after 1980) are more likely than their elders to blur the lines between work and home. Some 81% of them think they should set their own work patterns. For some, that might involve virtual meetings (by Skype, for example) rather than real ones, the opportunity to work from home when they want to and, ideally, a no-recrimination clause in their contract that would be activated when they tell their boss to shove it when she asks them to work next Sunday.
Well, we can all dream. What's workable is, of course, another matter.
Don't you deserve a little time off? Photograph: Getty Images