Split-testing banners is a smart way to see what works best. Start by changing only one thing at a time, like the headline, color, image, or call to action. This makes it easier to know what caused the change in results. Run your different banners at the same time under similar conditions so the test stays fair. Give the test enough time and impressions before making a decision. If one version clearly gets more clicks or conversions, then focus more budget on that one. Avoid testing too many versions at once so the data stays clear. What has been your experience with testing banners like this?