Intention on entering Ihram
اللَّهُمَّ لَبَّيْكَ عُمْرَةً
Allahumma labbayka 'Umrah
O Allah, here I am for Umrah.
Sahih Muslim 1218
Ihram is both a state and an intention. It begins at the miqat and continues until the rites of Umrah are complete.
The five miqat points are Dhul Hulayfah, Al-Juhfah, Qarn al-Manazil, Yalamlam and Dhat 'Irq. A pilgrim must not pass their miqat without entering Ihram.
Avoid cutting hair or nails, applying perfume, hunting, contracting marriage and marital intimacy. Men avoid sewn garments and covering the head; women avoid the face veil and gloves.
اللَّهُمَّ لَبَّيْكَ عُمْرَةً
Allahumma labbayka 'Umrah
O Allah, here I am for Umrah.
Sahih Muslim 1218
فَإِنْ حَبَسَنِي حَابِسٌ فَمَحِلِّي حَيْثُ حَبَسْتَنِي
Fa in habasani habisun fa mahilli haythu habastani
If anything prevents me, then my place of exiting Ihram is wherever You prevent me.
Sahih al-Bukhari 5089
Yes, with unscented soap. Washing is permitted; scented products are not.
You should enter Ihram before crossing the miqat in the air. If you pass it, return to the miqat if possible, otherwise an expiation is due.