Witches use many things when casting spells: Cords, Candles, Athame (knife), Besom (broom), Cauldron, Chalice, Sword and Wand - but these are effectively props, since it's what is happening in the witch's mind that is more important.
The successful spell-maker needs to develop the ability to visualise, to concentrate, to move into a state of altered consciousness or trance and to develop etheric energy, known by some as Chakras.
Magic rarely happens overnight - it takes time for a spell to work. When something is meant to, it will do so in its own time, not simply because a spell has been cast. It may be immediate: magic made to restore someone to health maybe brought to fruition right away, but it may take weeks, even months to work.
What can happen immediately is a sudden surge of confidence within the spell-weaver that a spell will work - and that in itself, is MAGIC.