If you are fitting your kitchen yourself here’s some helpful advise

Take accurate measurements, and take into account where your pipes, gas, electrical supplies are.
Make sure you know the sizes of your appliances.
Position the sink and dishwasher close together in order to make the plumbing easier.
Have a drawer unit close to the hob so that you easy access to any utensils.
Read through the instructions of your appliances before you decide where to place them.
Do not situate your cooker below any windows.
Check which way doors and drawers open in order for them to open fully.
Any tall units should be placed next to each other; tall units usually go at the end of a line of cupboards.
Position cupboards so that they are easily accessible.
It is always best to use a qualified tradesman for installation of any gas or electrical objects.
Having an extractor fan requires access to an external wall, unless you wish to recycle.

More helpful advise on design

The narrowest of kitchens can work well and look spacious, despite its proportions – just stick to a few basic design rules…

Unit-free walls Narrow rooms benefit from not having wall units, which just make them feel more cramped. Instead, put up glass shelving or paint shelves to match walls.
Fit flat fronts In the narrowest of spaces, detail-free doors will simplify the space and help it feel wider. Add to that impression by choosing a reflective finish – this also helps to widen a narrow room.
Keep floors simple Matching the tones of the floor tiles to those of the unit doors, and laying them lengthways across the kitchen, widens the room visually. To hieghten space, avoid patterned tiles or checkered effects.
Hide appliances It’s worth buying integrated appliances for small kitchens – they’re more expensive, but the effect is a streamlined space that is easier on the eye. If they must be on show, choose just the one finish – ideally stainless steel – and ensure they’re pretty.
Find a focal point Every room needs a focal point, and a galley kitchen is no exception – fit a fabulous showpiece, such as a range cooker, and the eye will be drawn to that and not to the narrow confines of the walls.
Make worktops work Small kitchens will always be more successful with lighter coloured worktops, and it’s a good idea to avoid finishes with pattern or detailing in them, too.