Clipping the nails, trimming the moustache, shaving and cleaning the hair of the armpits and below the navel. However, no ruling is found regarding men or women cutting the hair of their heads before entering ihram. It should be noted that the beard must not be cut under any circumstances. It is also mustahabb to perform ghusl after clipping the nails and cutting the hair.
وُقِّتَ لَنَا فِي قَصِّ الشَّارِبِ وَتَقْلِيمِ الأَظْفَارِ وَنَتْفِ الإبِطِ وَحَلْقِ الْعَانَةِ أَنْ لاَ نَتْرُكَ أَكْثَرَ مِنْ أَرْبَعِينَ لَيْلَةً
A time limit has been prescribed for us not to leave trimming the moustache, clipping the nails, cleaning the armpits, and removing the hair below the navel for more than forty nights. (Muslim 258)