Dimensions
The most important thing is that the cage is long and gives the canary the space to fly. These cages are often also called “flight” cages. It can be also high, if you have the space for it. The canary will definitely have its favorite spot somewhere high. But if you have to choose between a long and a high cage, go for the long cage.
Material
The wooden ones are very beautiful but not ideal for cleaning. So it is recommended to get a wire cage for easier cleaning. Since cleaning is important in order to keep your canary healthy, preferring a cage that is more functional and quick to clean is way much better than a cage that looks nice but remains dirty for longer periods.
Position
The cage position is also important. It should be never held in an area where there is draft or direct sunlight without any covers. The canary should always have the option to stay in the shadow, cause it is pretty fast for a canary to become overheated and this can lead to death. An ideal position would be close to a window but take care that all the time there is a place with a shadow for them.
If you have more pets or kids, make sure that they do not reach the cage and frighten the canary.
Remember: Covering the cage lets them sleep the hours, that they would sleep also in the nature and lets them rest.
Below we have a post about artificial light