Namaz is the most important among all acts of worship. If it is accepted by the Almighty Allah, other acts of worship are also accepted. And, if prayers are not accepted, other acts are also not accepted.
Offering of prayers five times during day and night purifies us of sins in the same manner as bathing five times during day and night makes our body clean of all filth and dirt.
It is befitting that one should offer prayers punctually. A person who considers prayers to be something ordinary and unimportant is just like one who does not offer prayers at all. The holy Prophet has said that a person who does not attach any importance to prayers and considers it to be something insignificant deserves chastisement in the hereafter.
Once, while the holy Prophet was present in the Mosque (i.e. Masjidun Nabi), a man entered and began offering prayers but did not perform the Ruku' and Sajdah properly. The holy Prophet said: "If this man dies and his prayers continue to be this way, he will not depart on my religion". Hence, one should not offer one's prayers hurriedly. While offering prayers one should remember Allah constantly and should offer the prayers humbly and with all solemnity. One should keep in mind the Greatness of Almighty Allah with whom one communes while offering prayers and should consider oneself to be very humble and insignificant before His Grandeur and Glory.
And if a person keeps himself absorbed in these thoughts while performing prayers he becomes unmindful and oblivious to himself, just as when an arrow was pulled out of the foot of the Commander of the Faithful, Imam Ali (peace be on him) while he was offering prayers but he did not become aware of it.
Furthermore, one who performs prayers should be repentant and should refrain from all sins and especially those which are an impediment in the way of acceptance of one's prayers (e.g. jealousy, pride, backbiting, eating haraam things, drinking intoxicating beverages, non-payment of Khums and Zakat). In fact, he should refrain from all sins.
Similarly, he should avoid acts which diminish the reward for prayers like praying when one is drowsy or restless because of an urge to urinate, and while offering prayers he should not look up towards the sky. On the other hand, one should perform such acts which increase the reward like wearing an Aqiq, wearing clean clothes, combing the hair, brushing the teeth and using perfume.