Before bagsying the best seat on a plane, you need to know which one it is, right?

For those of us not in scattered rose petal class, choosing a good seat - even in economy - can make for a far better flight

Find a good seat on a plane and you'll enjoy a quiet, smooth flight, with extra legroom, and a view of the Himalayas; a bad one and you'll be buffeted, half deafened, hemmed in on both sides, and next to a smelly loo unable to recline your seat.

Getting a good seat used to be all about smiling sweetly at the check in staff and hoping for the best. Now technology has put the choice in our hands, albeit at a price, leaving us to check in online or pick our seats at self-service machines.

So, it's important to know the difference between a good seat and a bad one, and which of the good ones is going to suit you best. Here are some general rules...

For more legroom.
Seats at the emergency exits have extra legroom, because they are further from the seat in front to assist a speedy evacuation. On larger planes, it can mean there is no seat in front, just a yawning gap to stretch out in. if you prefer easy access to your carry on luggage, note that in emergency exit seats, everything must be stowed in the overhead luggage racks for take off or landing. And some emergency exit seats don't recline (for example on an Airbus A320, the first of the two over-wing emergency exit seats).

For toddlers.
Most of us avoid the smells and commotion of the toilet and galley areas, but if you are travelling with a toddler, you'll benefit from a nearby loo, and the extra attention from the crew stationed in the galley.

Diagram showing some of the movement types that a plane will experience in flight

For avoiding turbulence.
The centre of gravity on a plane is just behind the front of the wing. Sit near it and you'll cut down the amount of movement during turbulence. The further from the 'centre' you move, and particularly to the rear of it, the bigger the up and down movements, called pitch (though not to be confused with 'seat pitch', which is a measure of roominess between seats), and the side to side movements, called yaws. Even during smooth flights, people susceptible to travel sickness are better off towards the 'centre' of the fuselage.

For nobody in front.
Larger aircraft have bulkheads, which are internal walls used to strengthen the fuselage. The row of seats immediately behind a bulkhead have a few extra inches of legroom. Also, there is no seat in front that can be reclined. Beware though, bulkheads mean bassinet positions too, which are where wall-mounted cots and screaming babies are usually located. And there's no floor storage, so bags have to be put in the overhead luggage racks for take off and landing.

For a quiet flight.
Jet engines push the noise out behind them, which makes the seats at the rear of the fuselage much noisier than those at the front. However, it's the reverse in a propeller plane, where the noise comes from the actual propeller blades cutting through the air. The blades are in front of the wing, so that the forward seats are nosier. Before advances in soundproofing, this explains why business class was often located at the back of prop planes.

For a view.
It's very annoying to book a window seat, and then find that you are sat by a blank wall. Often, there isn't a window at the row level with the front of the engines - where the fan blades rotate inside a jet engine, or the propellers on a propeller engine. For extra safety, engines can contain a snapped off fan blade inside the engine itself, but many aircraft types still have no windows here, to allow for reinforcing of the outer shell of the fuselage.

For not seeing business.
On smaller planes and short haul flights, the divider between economy and business can be a simple curtain across the back of the seats. There's nothing worse than sitting in this row and glimpsing the better service, or smelling the hot food from the cabin in front.

Airline Website will often have detailed seat maps of their aircraft, if not before, then certainly at the point where you check in. For good information seating plans and seats, see www.seatguru.com and www.seatexpert.com.