there are many things that fuel a witch's power, that can help us through spells when we have problems or just doing work in general.
Nature- The most common and basic source, we should have a connection to nature and maintain balance with her, as her energies of creation can have a dramatic effect on your spells.
Amulets/talismans, These can be special items to help you focus energies from the universe.
Astrological events, things such as comets,meteor showers have their own energies which we can manipulate to our desire
Emotions, emotions can dramatically effect your spells success as it can tie into will power. And based on the type of spell you are casting the desired emotion should be felt, you can't cast a love spell with a dislike for the person.
Animal bones/human bones - Bones have specific ties to divination and death energy in particular, but it can be used for a variety work.
Familiars, familiars are animal helpers that some use in their spell casting.
Ancestors- For people who's family line has magickal practitioners, these ancestral spirits can be called to fuel work with the witch.
other witches, more than one witch casting the same spell can make is stronger, it also can incorporate fuels listed before
seals and sigils, special symbols and drawings that has certain energy resonance, they are used frequently in enochian magick