Reference : Hisn al-Muslim 6

اللّهُـمَّ لَـكَ الحَـمْـدُ أنْـتَ كَسَـوْتَنيهِ،
أََسْأََلُـكَ مِـنْ خَـيرِهِ وَخَـيْرِ مَا صُنِعَ لَـه،
وَأَعوذُ بِكَ مِـنْ شَـرِّهِ وَشَـرِّ مـا صُنِعَ لَـهُ
Allāhumma lakal-ḥamdu 'anta kasawtanīhi, 
'as'aluka min khayrihi wa khayri mā ṣuni`a lahu, 
wa 'a`oothu bika min sharrihi wa sharri mā ṣuni`a lahu.

O Allah, praise is to You. You have clothed me. 
I ask You for its goodness and the goodness of what it has been made for,
and I seek Your protection from the evil of it and the evil of what it has been made for.

Reference:
Abu Dawud and At-Tirmidhi. See also Al-Albani, Mukhtasar Shama'il 
At-Tirmidhi, p. 47.

Chapter: When wearing a new garment