To edit photos in Serif Photo Plus, the user first inserts an image and uses tools like PhotoFix to adjust lighting and effects like filters to achieve different looks. They applied effects like glass and blur to focus on characters and experimented with comic and Gaussian effects. They also darkened images for depth, erased backgrounds and composited images onto new backgrounds, blurring the result. In the end, they produced two edited photos with adjusted lighting, effects and composited elements.