Here are three key SEO hacks that can be implemented right away to boost on-page optimization: 1. Optimize meta tags and H1 tags by including targeted keywords to clearly outline what the page is about and encourage clicks. 2. Make images more searchable by adding relevant keywords to image file names, titles, and alt text to increase traffic from image searches. 3. Ensure the website is responsive for all devices to provide a good user experience and prevent search engine penalties for being mobile-unfriendly.