The best way to send durood, is the way that the Prophet :saws:, the one upon whom durood is to be sent, taught his companions when they asked him. This has been narrated via many sound narrators, in authentic hadeeth. There are also some other versions of durood/salawaat with slightly different wordings in authentic hadeeth. These are the reports that we should be acting upon. While we are not limited to those reports, to believe that another type of durood/salawaat other than those mentioned in the authentic hadeeth is superior in reward, to the extent of the above, implies the prophet :saws: fell short in conveying to us what was of such tremendous benefit to us.
Narrated `Abdur-Rahman bin Abi Laila:
Ka`b bin Ujrah met me and said, "Shall I not give you a present I got from the Prophet?" `Abdur- Rahman said, "Yes, give it to me." I said, "We asked Allah's Messenger (sallallahu 'alaihi wa sallam) saying, 'O Allah's Messenger (sallallahu 'alaihi wa sallam)! How should one (ask Allah to) send blessings on you, the members of the family, for Allah has taught us how to salute you (in the prayer)?' He said, 'Say: O Allah! Send Your Mercy on Muhammad and on the family of Muhammad, as You sent Your Mercy on Abraham and on the family of Abraham, for You are the Most Praise-worthy, the Most Glorious. O Allah! Send Your Blessings on Muhammad and the family of Muhammad, as You sent your Blessings on Abraham and on the family of Abraham, for You are the Most Praise-worthy, the Most Glorious.' "
حَدَّثَنَا قَيْسُ بْنُ حَفْصٍ، وَمُوسَى بْنُ إِسْمَاعِيلَ، قَالاَ حَدَّثَنَا عَبْدُ الْوَاحِدِ بْنُ زِيَادٍ، حَدَّثَنَا أَبُو قُرَّةَ، مُسْلِمُ بْنُ سَالِمٍ الْهَمْدَانِيُّ قَالَ حَدَّثَنِي عَبْدُ اللَّهِ بْنُ عِيسَى، سَمِعَ عَبْدَ الرَّحْمَنِ بْنَ أَبِي لَيْلَى، قَالَ لَقِيَنِي كَعْبُ بْنُ عُجْرَةَ فَقَالَ أَلاَ أُهْدِي لَكَ هَدِيَّةً سَمِعْتُهَا مِنَ النَّبِيِّ، صلى الله عليه وسلم فَقُلْتُ بَلَى، فَأَهْدِهَا لِي. فَقَالَ سَأَلْنَا رَسُولَ اللَّهِ صلى الله عليه وسلم فَقُلْنَا يَا رَسُولَ اللَّهِ كَيْفَ الصَّلاَةُ عَلَيْكُمْ أَهْلَ الْبَيْتِ فَإِنَّ اللَّهَ قَدْ عَلَّمَنَا كَيْفَ نُسَلِّمُ. قَالَ " قُولُوا اللَّهُمَّ صَلِّ عَلَى مُحَمَّدٍ، وَعَلَى آلِ مُحَمَّدٍ، كَمَا صَلَّيْتَ عَلَى إِبْرَاهِيمَ وَعَلَى آلِ إِبْرَاهِيمَ، إِنَّكَ حَمِيدٌ مَجِيدٌ، اللَّهُمَّ بَارِكْ عَلَى مُحَمَّدٍ، وَعَلَى آلِ مُحَمَّدٍ، كَمَا بَارَكْتَ عَلَى إِبْرَاهِيمَ، وَعَلَى آلِ إِبْرَاهِيمَ، إِنَّكَ حَمِيدٌ مَجِيدٌ ".
Reference: Sahih al-Bukhari 3370
In-book reference: Book 60, Hadith 49
USC-MSA web (English) reference: Vol. 4, Book 55, Hadith 589
In the above hadeeth, this durood is called a gift from the prophet :saws:. What better gift than one from the Prophet :saws: himself?
Let us send our blessings on our beloved prophet :saws: in the ways the best of creation :saws: taught us, and no way is better than the way he :saws: taught.