Binoculars, flashlight, and a camera
Many useful checks do not require roof access. Binoculars help you scan shingle edges, valleys, and flashing lines for lifts, gaps, or debris. A bright flashlight helps in the attic or crawl spaces to spot staining, damp insulation, or daylight through decking. A phone camera is helpful for repeatable documentation. Take the same angle photo each season so changes are easy to compare.