All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
This verse is the verse number 17 from Surah At-Taghaabun [Quran 64:17]; and it generally applies to all what a Muslim spends and gives out of his property seeking thereby the Countenance of Allaah The Almighty, be it Sadaqah or Zakah.
As for the voluntary charity (Sadaqah), it would best be given to the needy relatives, in view of the statement of the Messenger of Allaah, sallallaahu ‘alayhi wa sallam, "Giving Charity to a needy is regarded as charity, and giving charity to a relative is regarded as both a charity and a maintenance of kinship ties."
On the other hand, the charity whose benefit remains effective after one’s death is the Waqf (endowment). This is what is meant by the statement of the Messenger of Allaah, sallallaahu ‘alayhi wa sallam, "If the son of Aadam dies, all his deeds cease save three: recurrent charity, or knowledge by which the people get benefit, or a righteous child to supplicate (Allaah to a good effect) for him."
So, if you wish to give a charity whose reward continues after your death, you should assign something of your property as an endowment for one of the charitable fields, and they are many. For more benefit, please refer to Fatwa 90156.
As for giving such objects of charity as clothes or so to the non-Muslims, then this is permissible and the Muslim will be rewarded for it. Nevertheless, satisfying the needs of Muslims, and seeking them out to give them charity is preferable and better.
Allaah Knows best.