Always lock your cycle in well-used and properly lit areas where it is visible to passing pedestrians if leaving it unattended.
Use a good quality lock that matches the value of your bicycle. If necessary use two different types - a D-lock as well as a flexible one.
Thread it through the frame and at least one wheel and secure it to something immovable, such as a cycle rack or railings.
Remove and take with you quick release valuables such as lights, pumps and panniers.
Ensure your cycle is easily identifiable. Make a note of model, frame number, colour and any accessories. Also photograph it and have the underside of the frame marked with a post code.
Insure your cycle and if it is stolen report it immediately to the Police.
There are a number of schemes where you can register your bicycle on a website but one recommended is Immobilise.
Bedfordshire Police regularly organise events where you can get your cycle marked and receive crime reduction advice.
A leaflet can be downloaded on how to keep your bike safe.