Set a calendar task that repeats every month to remind you to check your tire pressures. If your tires are under-inflated they have more rolling resistance than when correctly inflated which means you’ll use more fuel. Under-inflation also generates more heat in the tires which causes them to wear out quicker; in some cases, it can cause the tire to delaminate or disintegrate while driving. If they are badly under-inflated, there’s a risk they could roll off the rim when cornering sharply and, if you hit a pothole, the tires won’t have the resistance required to prevent damage to your wheel rim.
Don’t over-inflate them, either, because then you’ll have less tire in contact with the road, meaning less grip for cornering, braking and accelerating.
While you’re checking your tire pressures, check the tread depth, too. Anything less than 3mm and you should consider replacing them because their ability to disperse water decreases exponentially from there, increasing your risk of aquaplaning (or hydroplaning) and losing control in heavy rain.