1. Wash the right limbs before the left limbs.
عن أبي هريرة قال قال رسول الله صلى الله عليه وسلم إذا لبستم وإذا توضأتم فابدءوا بأيامنكم (سنن أبي داود، الرقم: 4141)
Hazrat Abu Hurairah (radhiyallahu anhu) reports that Hazrat Rasulullah (sallallahu alaihi wasallam) said, “When you wear a garment and when you perform wudhu, then commence from your right limbs”.
عن عائشة رضي الله عنها قالت كان النبي صلى الله عليه وسلم ليعجبه التيمن فى تنعله وترجله وطهوره وفي شأنه كله (صحيح البخاري، الرقم: 168)
Hazrat Aaishah (radhiyallahu anha) reports that Hazrat Rasulullah (sallallahu alaihi wasallam) would like commencing from the right side when wearing his shoes, combing his hair, performing wudhu and when carrying out all other works (i.e. all other noble works which require respect being shown to the right side e.g. entering the musjid and Ka’bah with the right foot, commencing from the right when wearing clothing, using the right hand to receive or give an item, etc.).
2. Rub each limb thoroughly when washing it to ensure that water reaches each part of the limb.
3. All the limbs should be washed, one after the other, without any delay in between.
4. While making wudhu, do not speak of worldly affairs.
5. Do not waste water while making wudhu.
عن عبد الله بن عمرو رضي الله عنهما أن رسول الله صلى الله عليه وسلم مر بسعد وهو يتوضأ فقال ما هذا السرف فقال أفي الوضوء إسراف قال نعم وإن كنت على نهر جار (سنن ابن ماجة، الرقم: 425)
Hazrat Abdullah bin Amr (radhiyallahu anhuma) reports that Hazrat Rasulullah (sallallahu alaihi wasallam) passed by Hazrat Sa’d (radhiyallahu anhu) whilst he was performing wudhu. Hazrat Rasulullah (sallallahu alaihi wasallam) asked him, “What is this wastage (of water in your wudhu)?” He replied, “Is there also wastage in wudhu?” Hazrat Rasulullah (sallallahu alaihi wasallam) replied, “Yes, even if you are performing wudhu at the bank of a flowing river (then too, be mindful of not wasting water).”
6. If any part of a limb which is fardh to wash in wudhu is left dry, the wudhu will be incomplete.
عن عمر بن الخطاب رضي الله عنه أن رجلا توضأ فترك موضع ظفر على قدمه فأبصره النبي صلى الله عليه وسلم فقال ارجع فأحسن وضوءك (صحيح مسلم، الرقم: 243)
Hazrat Umar (radhiyallahu anhu) reports that a man made wudhu and left out washing an area on his foot equivalent to a nail. Upon observing the portion that was left dry, Hazrat Rasulullah (sallallahu alaihi wasallam) said to him, “Go and complete your wudhu.”