“As far as the description of the `Umrah, then it is the following:
The worshipper should make intention and put on the ihram at the points of the miqat if he is passing by or if he is near and he is in his normal clothes. An example would be if he went to At-Tan`im and then changed into the ihram there after making intention.
The proof of this is where the Prophet, peace and blessings of Allah be upon him, after putting on ihram and doing `umrah and hajj said, “Learn your laws of `umrah and hajj from me and take hold of this requirement.” Collected by Imam Muslim in Al-Jami` us-Sahih and classed as authentic.
It is not permissible to put on the ihram in Al-Masjid ul-Haram as this is doing the opposite of what the Prophet, peace and blessings of Allah be upon him, commanded us to do for `umrah. If he does this, he will have to give a sacrifice for the mistake.
So after putting on the ihram, he goes to Al-Masjid ul-Haram and makes seven circuits, with the Ka`bah on his left. This is a hadith collected by Imam Abu Dawud and classified as authentic.
The supplication for seeing the Ka`bah for the first time is:
اللهُمَّ أَنْتَ السَّلاَمُ وَ مِنْكَ السَّلاَمُ حَيِّنَا رَبَّنَا بِالسَّلاَمِ. اللهُمَّ زِدْ هَذَا الْبَيْتَ تَعْظِيماً وَ تَشْرِيفًا وَتَكْرِيماً وَمَهَابَةً وَبِرّاً. وَزِدْ مَنْ عَظَّمَهُ وَشَرَّفَهُ مِمَّنْ حَجَّهُ وَاعْتَمَرَهُ تَعْظِيماً وَتَشْرِيفاً وَ تَكْرِيماً وَ مَهَابَةً وَبِرّاً. اَلْحَمْدُ لِلهِ رَبِّ الْعَالَمِينَ حَمْداً كَثِيراً كَمَا هُوَ أَهْلَهُ وَكَمَا يَنْبَغِي لِكَرِيمِ وَجْهِهِ وَ عَزَّ جَلاَلَهُ. اَلْحَمْدُ للهِ الَّذِي بَلَّغَنِي بَيْتَهُ وَ رَآنِي لِذَالِكَ أَهْلاً. اَلْحَمْدُ للهِ عَلَى كُلِّ حَالٍ. اَللهُمَّ إِنَّكَ دَعَوْتَ إِلَى حَجِّ بَيْتِكَ الْحَرَامِ. وَقَدْ جِئْتُكَ لِذَالِكَ. اَللَّهُمَّ تَقَبَّلْ مِنِّي وَ اعْفَ عَنِّي وَ أَصْلِحْ لِي شَأْنِي كُلَّهُ لاَ إِلَهُ إِلاَّ أَنْتَ.
This is mentioned by the students of the Companions, such as Sa`id ibn al-Musayyib, Ibn Juraij and others and collected by Imam Abu Bakr al-Athram, the student of Imam Ahmad ibn Hanbal.
After the seven circuits, he is to go to Safa and Marwah and make the seven journeys between them. After this, his `Umrah has been completed and he may either shave or cut his hair. This shaving or cutting of the hair must be done before he gets out of the ihram as it is a condition for the completion of the `Umrah.
`Umrah may be done any time, whether it is in the months or Hajj, the Day of Sacrifice or `Arafah. It is disliked to do `umrahs concurrently without any break between them and this is the Consensus of the first three generations as was quoted by Imam Burhan ud-Din Ibn Muflih.
There are three integrals that have to be done in order for the `Umrah to be valid and if they are not done – whether intentionally or unintentionally – the `Umrah will be invalid. The three integrals are:
2) tawaf around the House,
3) making the journey of Safah and Marwah.
This is based upon the hadith of the Prophet, peace and blessings of Allah be upon him, where he said, “Whoever is not required to bring any sacrifice, then let him make tawaf around the House, go between As-Safah and Al-Marwah, then let him cut his hair and come out of ihram.” Collected by Imams al-Bukhari and Muslim and classed as authentic.
Then there are actions that if intentionally omitted the `umrah would be invalid but if accidently omitted would not nullify the `umrah if compensated with a sacrifice. These actions are called wajibat and they are:
- Shaving or cutting short the hair,
- ihram at the miqat place with the intention,
- So whoever abandoned the ihram has not completed his hajj or his `umrah and in fact has never started.
This is just like the one who prayed without intention. Whoever left an integral besides the ihram or the intention, then his `umrah is not valid as he has left the integral or the intention. Whoever left a wajib has to have a sacrifice done for what was left in order to compensate the `umrah and have it counted as valid.” 
 d. 624 AH (AD 1227)
 d. 1051 AH (AD 1654)
 Trans. note: (at Masjid `A’ishah in Makkah, which is outside the boundaries of Makkah and is the closest area to act as a miqat)
 d. 885 AH (d. 1534)
 Please see Ar-Rawd ul-Murbi`, bi-Sharhi Zad il-Mustaqni, pp. 229-231.