This seeps into everything else now. I want to spend words on the casting of a spell, to show the reader by doing how the magic works and why, and- no, let me show you instead:
"Go ahead. I shall handle this, and I'll be with you lot presently." Robert drew a pouch from inside his doublet and smiled.
The others looked at each other, then at Robert. They nodded and departed, making haste as the growling behind them grew louder. Robert turned to face their foe. He opened the pouch and drew from it a ball of odious material the size of a marble. Hold it before his face, he drew in a breath and calmed himself as he focused his mind. The growling grew louder, and now in the torchlight he could see not one foe but a small pack of them. The growling differentiated into a dozen growlings, and their withered form revealed them to be ravenous undead revenants.
Robert saw fire in his hand, and then he saw words where the fire in his hand rested. The words he spoke, old and powerful, in the low-but-rising tone symbolic of an erupting blaze as he shook that hand as if to strike a spark. He felt the words hit the ball in his hand, and he saw a spark ignite the ball. Fixing his gaze upon a revenant just behind the leader, he cast the flaming ball down the way as if throwing a grenade, and then he shielded his eyes.
The growlings became squealings as the fire grabbed at them as if a hawk's talons, and then consumed them as fire consumes dry wood, leaving only charred bones behind. Robert's smile became a smirk, smug in satisfaction. Without hurry, he turned about to rejoin his companions.
Not bad, eh? Now, I wouldn't do that for every casting of a Fireball, but for the first time or for notable situations, I'd do that. Once I've put down what using magic, or flying a robot, or whatever, is like then I am free to play with it for purposes of dramatic effect or characterization.
Trying to do this with dialog is tricky, but applicable, as it involves making use of beats in the scene to fulfill that purpose. Until you get used to knowing when NOT to use "said", it's something to avoid in favor of doing the basics until you can't get them wrong; it's a Crawl Before You Walk thing.