The arrival of sharp misty mornings is depressing because it means another year has somehow slipped by, and we haven't even had a proper summer... Or, it's wonderful to watch the trees turning every imaginable shade of orange, red and gold, to snuggle up with buttery baked potatoes and other comfort food, and to reacquaint yourself with your favourite boots and woolly jacket.

You see it's all a matter of perspective. How we feel about things depends on how we look at them . Most of us have been asked at some point if we're half bottle full or half bottle empty kind of people. But what we don't always realise when we consider the answer is the amount of choice we have about what we think, and therefore how we're going to feel.

Try it for yourself next time you're stuck in the M1 roadworks. Either, you can decide this an infuriating delay which is going to throw everything out and is a waste of your time. In which case you're likely to feel angry, annoyed, frustrated, impatient – or all of those things together.

Or you can decide that since you can't do anything about the delay you'll put on some lovely music, take a look around at a part of the world and fellow drivers who you normally only glimpse at 80mph, and make the most of an unscheduled 15 minutes with your thoughts. You may not quite get to the point of feeling happy, but you probably will feel quiet pleasure at the way you're making the most of the situation.

Nothing has changed outwardly: only your perspective on your situation, and, as a result, the way you feel inside. To change the feelings, we need to change our perspective whenever negative thoughts are causing hurt to ourselves. And in doing so we can enjoy more of the good feelings – happiness, peace, hope, pleasure - which sometimes se em so hard to come by.

Easier said than done? Maybe, but only because of the years we've spent seeing things everyone else's way: from our parents and teachers through to all the messages we get from the society and world we live in, via the tv and newspapers, our politicians and community leaders.

So, for instance, most of us probably look out at wet streets and grey skies and think to ourselves ‘what a miserable day' because that's what we heard grown ups say when we were little (and what we now say to everyone else). So we start feeling miserable and head off into the day in a grey mood which will be self-fulfilling.

But it's not a miserable day. Only a wet one. And just remind yourself how much little children enjoy wet days, splashing about in puddles, trying to catch raindrops in their mouth – until they get told off for ruining their shoes!

We've all heard stories of people who manage to find peace, contentment, happiness in the most dire circumstances, among them some of those facing life-threatening illness who describe how their perspective on almost every aspect of daily life has altered – for the better. Things that used to matter, or to bother them , are suddenly exposed as trivial distractions, while the things that really do count become truly precious.

So how do you go about changing your perspective, even when life is frantic or you face some difficult times or choices, or everything's getting on top of you? Here are a few ideas to try:

Learn from your own experience

Think back to something that really worried you or kept you awake at night a few years ago. How do you feel now about what was going on then? It's amazing how viewing things through the perspective of passing time takes away the sting of most of the things that once caused us pain.

Look to the future

Alternatively, when something is really getting to you, imagine yourself at the age of 80, looking back on your life. What are the things you will want to be thinking about then? Will whatever is troubling you now still matter? Will it still have the power to hurt or worry you? In the context of a long life well lived, how important will it be?

The lessons of experience

In a notebook run through some of the major challenges or upsets you've faced in your life and then write down anything positive that came out of each of them : did you learn something or did they change you in some way? With the benefit of hindsight, we often find that situations that hurt or troubled us were actually for the best. Or altered the direction of our lives in a way that has brought us a different or richer experience. The next time you're struggling remind yourself of those times.

See the funny side

A while back I went to the funeral of a friend who knew his loved ones well enough to anticipate there'd be plenty of tears – so he left instructions that he was to be played out to the tune of The Laughing Policeman. Now, whenever I start to take things too seriously, I play back the memory of that song blaring out and everyone breaking into a laugh. Find a memory that makes you smile or laugh and keep it in reserve for times when you're struggling to stay positive.

Get some distance

Paul McKenna is only the latest ‘guru' to show how by visualising your problems getting smaller you can get a healthier perspective on them . Whether it's a person or situation that's getting you down, close your eyes and picture it slowly shrinking until it's no more than a pinprick.

And finally, remember, as the book says: Don't sweat the small stuff… ps. It's all small stuff