As John says (although he says it with scientific precision).

Look at the tyre. If the sidewall shows cracking or bulges, replace it.

Kick the sidewall.

Inflate sufficiently and do not overload. Normally if the inflation is insufficient (or there is an overload) you will feel it in the vehicle's handling. I commonly stop after a few miles on the motorway to feel the tyre temperatures. Heat generation is a square law.

Feel or any unusual vibrations or a tendency for the steering to pull, while driving.

Be "vehicle sensitive".