To optimize your Facebook ad campaigns using A/B testing with EcomTushar, start by creating two or more variations of your ad, each differing in a single element like the headline, image, or call-to-action. Run these ads simultaneously to a similar audience to gather data on performance metrics such as click-through rate and conversion rate. Analyze the results to determine which variation performs best and use these insights to refine and enhance your future ads. EcomTushar's tools can help streamline this process and provide detailed analytics for more informed decisions.