There is no specific ritual act that should be observed to commemorate the Prophet’s birthday. However, the best way is to worship Allah, attain His Pleasure, and show love and adherence to His Message is by following in the Prophet’s footsteps.

Sheikh Ahmad Kutty, a senior lecturer and Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada, states the following: We are allowed to commemorate the event of the Prophet’s birth by offering charities and performing optional good works that are always permitted in Islam. However, it would be even better to seize the opportunity to educate ourselves and others about the great benefactor, the Messenger of mercy and to express love for him by following in his footsteps. Saying salawaat (prayers) and nasheeds in praise of the Prophet (peace and blessings be upon him) are noble deeds. Sending salawaat on the Prophet (peace and blessings be upon him) has been enjoined in the Qur’an. Praising the Prophet (peace and blessings be upon him) is also an established tradition that we inherited from the time of the Prophet (peace and blessings be upon him), thus, no one can consider it to be bid`ah (an innovation) in religion.
Having said this, however, I must also make it clear that we must never exceed the limits by equating the Prophet (peace and blessings be upon him) with Allah. This would be the case if we were to attribute divine powers to him or to take him as an intermediary in worship.
Our love of the Prophet (peace and blessings be upon him) must be expressed without any taint of shirk (disbelief). In fact, celebrating the great life of the Prophet (peace and blessings be upon him) will go a long way in uniting Muslims together on the event that all of them will be proud of. So there is indeed a great benefit in these times, especially because Muslims are in need of a unifying event. There is nothing more important for humanity than the coming of the mercy of the worlds. May Allah fill our hearts with the love for His Messenger (peace and blessings be upon him).Ameen.