Trees that remain sturdy and upright when first planted do not need to be staked. Otherwise, stake trees just enough to keep them upright and stable in harsh weather. Generally, you should not leave trees staked for periods longer than eight months; any longer than that and the tree may get damaged by the staking materials.
You can also stake perennials to maintain a neat appearance in the bed. They sometimes flop around, and staking holds them upright. The common method uses garden stakes and loose twist-ties to secure plants to the stake. There are also various wire hoops you can purchase from your local nursery. If you use wire hoops, put them in place when the plants are small. Then the plant will grow through the hoop nicely.