Ultimately, therefore, three "zones" ought to be created: the storage zone, cooking zone and washing zone. The tough balance to strike is ensuring that these three areas are not too far away from one other, as you don't want to trek too far with a hot pan, heavy dish or a stack of dirty crockery - but at the same time, they're not surrounding you to the point of feeling claustrophobic or short of room.
With this in mind, get your measurements correct first. You do not want to have to walk more than three paces between two of these three focal points; however, the ideal distance is probably only one or two footsteps, though it ultimately depends on your kitchen's size.
If you're looking for a starting point to define your working triangle, then it's always best to focus on the sink in its current position. The problem with plumbing projects is that they usually cost more than people are willing to pay. Most modern kitchens will have the sink in the best place to begin with, against a wall or window to allow for outdoor drainage.
Secondly, the cooking area should be carefully considered. While the fridge is obviously important in any kitchen, it is also the most flexible, and so usually becomes the final stage of work triangle planning. It is important to remember that the cooking area must be expanded to include the countertop hob, as well as other cooking apparatus, such as a microwave - now a kitchen staple - and other newer inclusions, such as a steamer. A lot of modern kitchens use combination oven/microwaves, or will pair them up in a vertical stack, and in the triangle it's important to see why.
As the last part of creating the kitchen work triangle, try to ensure that the fridge and freezer occupy the same space. While this is not always easy in a kitchen that already dedicates two areas to both appliances separately, everything else should be moved around to unify these items, even if they are side by side (though preferably stacked). Remember that other kitchen staples - washing machines, dryers and dishwashers - occupy similarly-sized spaces that can be reimagined in a full kitchen redesign.
Finally, remember the importance - and effects of - traffic flow through a kitchen. Parallel or single-wall kitchens with doors at either end may present an insurmountable challenge to this principle, though traditional two- or three-wall kitchens will naturally offer a space where the triangle is unused by people not involved in the preparation of food.
Luckily, architects and designers have been following these principles for decades, so chances are that a lot of the groundwork will have been carried out before redesigning your kitchen. Nonetheless, if you're being adventurous with your home, don't forget this all-important factor for comfort and usability!