Casting most spells requires 5 seconds of appropriate roleplaying including some sort of shout, chant or speech throughout. You may then indicate a target and make that call at them. For example “Bob! MAGIC TRIPLE!” or “Skeleton in the Hat! MAGIC TRIPLE!”. Some may be cast with a short phrase such as BY MY POWER, or FOR THE ASPIRANT, followed by the target and spell effect. These spells are noted as "instantaneous".
Whilst casting a spell you must hold a focus. A focus is some sort of object that represents how your character enforces their will on the world. It might be a fancy wand for a Mage, a holy symbol for a priest, or a bottle o’rum for a vicious pirate. Foci must be obvious, appropriate to the character, and visible to an observer. They cannot be a ring you are always wearing, a coin hidden in the hand, etc. The idea is that holding a focus is roughly equivalent to holding a gun or pointing a magic wand. Anything about fist-sized is definitely OK. Rule 7 applies, check with Refs if you're not sure. Foci are magic items and will have a blue ribbon on them.
Foci cannot be used as weapons or to parry and should not resemble weapons. You do not count as holding a focus if there is also a weapon or shield in that hand. If you lose a focus, you may bond to a new one by finding an appropriate item and performing 60 seconds of appropriate roleplay. The ref will let you know if the item is an acceptable focus and hand you a new ribbon.