The best time to trim bushes depends on the type of bush.
Spring-blooming bushes: Trim after flowering, usually in late spring or early summer.
Summer-blooming bushes: Trim in early spring before new growth emerges.
Evergreen bushes: Trim in late winter or early spring before new growth starts.

The frequency of trimming depends on the type of bush and your desired shape. Generally, you'll need to trim once or twice a year.
Fast-growing bushes: May need trimming more often.
Slow-growing bushes: May only need trimming once a year.

For basic trimming, you'll need:
Hand pruners: For small branches.
Loppers: For branches thicker than 1 inch.
Hedge shears: For shaping hedges or large bushes.

Use clean tools: Disinfect your tools between uses to prevent the spread of diseases.
Avoid trimming during wet weather: This can increase the risk of fungal infections.
Remove and dispose of any diseased branches: Proper disposal will help prevent the spread of diseases.

Pruning techniques differ depending on the type of bush and desired shape:
For shaping: Cut branches at an angle to promote healing and keep the bush neat.
For removing dead, diseased, or damaged branches: Cut at the base or just above a bud.

Plan your trim: Consider the overall shape and desired look for your bushes.

Start small: Remove a little bit at a time and adjust as needed.

Use hedge shears to create a consistent shape.
Trim the top and sides evenly to create a boxy or pyramid shape.
Consider creating a natural shape by trimming to follow the bush's natural form.