Using dedicated procedure
As soon as an unfavorable speed trend develops, pilots must take action and prevent a speed exceeding, following the operating techniques and recommendations detailed in the OVER SPEED PREVENTION procedure.
In most cases, the use of  OVER SPEED PREVENTION procedure will effectively prevent exceeding Vmo/Mmo. Nevertheless, due to system design and limited authority this may not be sufficient. For this reason, an OVER SPEED RECOVERY procedure is developed as well and implemented in the FCOM/QRH.
The OVER SPEED warning is triggered when the speed exceeds Vmo+4 kt or Mmo+0.006, and lasts until the speed is below Vmo/Mmo. In this case, the flight crew must apply the OVER SPEED RECOVERY procedure.

Maintaining the aircraft after exceeded Vmo/Mmo 
The flight crew must report any type of OVER SPEED event (i.e. if OVER SPEED WARNING is triggered).Indeed, in case of an over speed, an inspection of the aircraft structure may be required.
Indeed, when an over speed event occurs, the aircraft may experience a high load factor. Only an analysis of flight data allows to tell whether or not an inspection is required.
This support the crucial need for flight crews experiencing an over speed to report it. Then maintenance and engineering teams will judge whether or not further inspection is needed.
In cruise, the aircraft airspeed might not be the desired one at all times. The aircraft may encounter adverse weather and turbulences, over even winds, which all have direct impact on the airspeed. For this reason flight crews must remain vigilant at all times and anticipate the main treats to the airspeed by planning ahead and communicating.
In practice, once the aircraft is airborne, pilots must be fully cognizant of the airspeed as well as the speed trends at all times in flight. In case of need, the FCOM/QRH and FCTM provide procedures and adequate guidelines to prevent and to recover from a speed excursion, and react wisely to any variation of airspeed. They are worth being thoroughly read and understood in advance.