You can spot quite a lot from the ground and inside the house. Step back and look at the roofline from different angles. Do you see sagging, dips, or areas where the surface looks uneven? Use binoculars if you have them to check for broken, curling or missing shingles, and debris piles in valleys.
Inside, inspect ceilings and top corners of rooms, especially after heavy rain. Any brown stains, bubbling paint or damp patches hint at leaks. In the attic, look for daylight peeking through where it shouldn’t, or signs of water trails on wood.
Also check gutters from a safe position. Overflowing, crooked or heavily clogged gutters can cause water to back up under roof edges.
You don’t need to become a roofer yourself. These simple visual checks once or twice a year give you enough information to call a professional on time, before a small issue becomes a messy interior leak.