Divination, speaking/remembering passed loved ones, spells for new beginnings because it's seen as 'Pagan New Year'. A lot of love divinations and spells are traditional on Samhain/Halloween. All Hallows Eve is the Christian holiday before All Saints Day where you lock yourself in your house and pray no spirit or witch attacks. [No offense, I'm joking]
If a spell for any of the above things are cast, it is believed to be stronger, but it doesn't mean a curse or a beauty spell won't work today, it just means the energy on this day is attuned to certain spells.