For spells, you can pick spell names and effects out of a D&D book of any edition, or, to be more creative, invent spells on the fly. For authentic flavor made-up spells should be named using the Name-Adjective-Noun(ish) format. “Cure Light Wounds” is boring; I always wanted to cast something like Garbledor’s Astonishing Recovery. Fireball? Feh. Try Faldoron’s Spectacular Holocaust.
I never played magic-users for more than a single adventure, but I always thought that casting Bigby’s Crushing Fist or Drawmij’s Instant Summons sounded much cooler than casting the generic Magic Missle. However, I will say that while Rary’s Mnemonic Enhancer has much more flair than a plain old Fireball, it doesn’t do squat for you in a pinch when your party gets bushwhacked by a band of frost giants.