Faster speed, clearer headlines, content that matches what they searched.
Speed first. Every extra second of load time increases bounce rate by around 20%. Next, match intent. If someone clicked your link expecting X and you show them Y, they leave. Your headline and opening line must communicate value immediately. Add internal links so visitors have somewhere logical to go next. Make the CTA obvious and single. Fix mobile usability. One note: not all bounces are bad. A visitor who reads your contact page in full and calls you will register as a bounce. Context matters more than the number.