What happens when the phone is ringing, the word 'multitasking' is woefully inadequate to describe the number of projects you have on the boil, and suddenly a complex and curious piece of work turns up that just cries out for ingenuity? How can you set up the conditions to think creatively in a manageable way?

The first step is to make yourself immediately familiar with the task, and then back off. Do not delay looking at it 'for a good moment' or you lose valuable background processing time. Assess the basics. Maybe compile a list of its challenging features. Describe it to a friend. Think about how you will feel when you've completed it.

Find some resources that will broaden your thoughts (such as www.visualthesaurus.com or www.buildingbrands.com ready for the next step.

Get engaged, but don't start to plan. You need something for your subconscious to chew over while you go on with other tasks. If you can bear it, tell yourself what you are doing: 'Over to you now, brain, while I arrange accommodation for this conference,' or whatever.

Next, decide when you will return to it. Walt Disney had three rooms built for creative work: the first for the dreamer, the second for the planner/realist, and the third for the critic. People developing his cartoons moved from room to room as they went through the creative process, taking an idea from possibilities, to practicalities, to testing its robustness. In this way, he made explicit the different stages that lead to novel and useful outcomes.

Most of us tend to rush through these stages or mix them up. So, the second step is to plan for this sequence. Put aside, at minimum, two short chunks of time. Deliberately leave all the fine-tuning and criticising till the second of these.

Police yourself - all planning and criticising is banned. Make a time when you allow yourself to play with ideas, however loosely formed. Exercises like: 'What is the funniest/worst/ideal way of doing this?', or 'List 15 ideas in five minutes!' are useful. Or try out the websites above. If you draw a blank, think how someone you respect for their skills would handle the exercise and do it through their eyes.

Don't force yourself and don't punish yourself. (Thinking about the deadline will kill all known ideas.) But do trick yourself: imagine the project is done - how would you describe it? The best state for this truly is close to dreaming: the hazy way you sometimes feel when you're lying in bed and you don't have to get up in the morning. Go for soft focus...

And, while you don't need a special room, you do need space. Get a specific length of time freed up without interruption. Divert your phone and stare across the room: imagine, doodle, sketch. If the prospect makes you feel guilty, you may have to take this stage into your own time. Baths are good places to think. Driving, walking and washing up also offer the right mix of manual distraction and freed brain. Keep a pad handy for capturing your insights.

Then, at the next occasion (and this can be half an hour, or two weeks, after your ideas session, depending on your schedule) sit down and tease out what you've collected. Take each thought and see what it offers. Add, extend, interrogate and think through. Be patient and be thorough. See if anyone else is around to help talk it out. This is where the earlier madness suddenly turns into the seed of a plan.

And do remember that the zone of uncertainty you occupy, as you struggle for a solution is the place that professional designers like to be. They see it as a mountaintop, from where they have many paths down. Some paths will be more visible than others. They look closely at the terrain before stepping, because once started, much of their choice is gone. If casting around and playing 'what if' games seems dangerous to you, you have the rest of the world with you on that. But pause for thought goes a long way in problem solving.

Still feeling daunted? Many of us get our creative confidence squeezed out early on, as parents, schools and jobs emphasise getting things right. But bear in mind that even most inventors are actually applying a familiar idea from one field to another when they solve a problem. The resources are around you and within you; it's just a question of giving them the space to appear.