Katia Martins completed various photo editing tasks in Photoshop, including cropping images, adjusting colors, fixing red eye and skin imperfections, and combining multiple images. Tasks involved using selection tools like the marquee and lasso tools followed by adjustments to colors, brightness, contrast and other properties to refine the images. For one task, green eye color was created by selecting and adjusting cyan levels. Overall, the document outlines Photoshop techniques used for tasks like retouching, color manipulation and compositing images.