What to do, and when

Keep the penetrations honest

Pipe boots crack, sealant shrinks, and satellite mounts get screwed straight through the covering. Every penetration is a hole somebody decided to make watertight, and each is worth a look.

Look in the attic after heavy weather

Check after the first real weather of the season rather than at the end of it. A small stain found in autumn is a cheap repair; the same stain found in spring is not.

Deal with growth properly

Cleaning a roof aggressively does more damage than the growth was doing. Gentle treatment, patience, and a strip at the ridge to stop it returning.

Cut back anything touching the roof

Branches abrade the surface in wind and drop debris that holds moisture. Keep growth well clear of the covering, and clear of the gutters while you are at it.

Clear the gutters before the wet season

Blocked gutters back water up under the bottom course of shingles and rot the fascia behind them. This is the highest-value hour of maintenance there is, and here it wants doing before November through March.

Twice a year, from the ground

Walk the perimeter with binoculars if you have them. You are looking for missing or lifted material, dark patches, sagging lines, and anything growing where it should not be. Ten minutes, twice a year.

In short

None of this is difficult and none of it is expensive. It is simply the difference between a roof that reaches its rated life and one that does not.