After a general 5 minute warm-up, always make sure to warm-up those muscles that will be utilized in the strengthening activity.

Always stretch muscles before, after, and during activity. This helps prevent soreness.

Perform movements in a slow and controlled manner. Never use momentum or bouncing movements, as this may cause injury.

Make sure to perform movements with correct form, especially if working with weights.

As with any exercise program, always start slowly and gradually progress as your skill level increases.