Finish a long rest.
Good morning! You woke up refreshed, and so did all your spell slots. Now where did you leave that prepared spell list? If you're happy with your selections from the day before, go have a nice omelette of Dire Hen eggs. But if you’d like to cast any different spells today, choose from the ones in your spellbook and study them. It will take at least 1 minute per spell, so hopefully you weren’t woken up by an angry Dire Hen.
Check your material components.
If any of your spells require components with a cost, or components which are consumed by a particular spell, make sure you possess the necessary items. That way you can actually cast those fearsome magicks when the time comes. No-cost, unconsumable items may already be in your component pouch, or made unnecessary by your spellcasting focus. Good thing you picked up that Arcane Fedora.
Now — you’re ready to start your day.
After a short rest.
Nice battle! You really saved the ranger's bacon. You spent some spell slots, though. If you’re running low, you may want to use Arcane Recovery to get some back. You can use this ability one time between long rests, following a short rest. Come to think of it, you rest a lot. Your mother and I are concerned.
Oh, you looted those bodies and found a sweet spell scroll? Nice! If you’d like to save that spell in your spellbook, take 2 hours to transcribe it. And watch it vanish from the scroll when you’re done. And fork over 50 gp for “expenses.” Take your time; we’ll wait. The half-orc barbarian loves watching you work. And sharpening that scimitar with a stone. Always with the sharpening.
18th level wizard or higher?
While you're busy being all fancy and high-level, don’t forget to use your two no-slot-required Spell Mastery spells — you get them after every long rest, remember. If you don’t like the two you currently have prepared, ask the party to take an 8-hour break while you study long enough to replace these 1st- and 2nd-level spells. I’m sure they won’t mind the random encounters.
If you’re a 20th-level wizard
Well, you’re essentially a demigod. Light on the “demi.” But you picked out these two no-prep, no-slot, 3rd-level Signature Spells, so, “use it or lose it." Maybe you chose Glyph of Warding, in case a troupeau of Tarasques tries to sneak up on you while you sleep. Or maybe Major Image, because Netflix hasn’t been invented yet. I hope you chose wisely, because your Signature Spells can’t be exchanged. No store credit for abjurations, as the sign says. But no matter. You’re a 20th. Level. Wizard. You've got this.
Now it’s off to bed, to dream of tomorrow’s newly-restored spell slots.
It's hard out there for a wizard. There's a lot to keep track of. Perhaps you could use something like Wizard: Can I Cast This Spell? a convenient spellcasting diagram and lexicon: It shows the various requirements and options for harnessing the unimaginable might of arcane forces — in a handy flowchart format.
Perfect for new wizards who are just starting out and have like 37 tabs sticking out of their Player's Handbook. Or experienced wizards who sometimes forget to prepare new spells because it's all pretty instinctual now and aren't material components a pain and um sure that one's deffo in my spellbook I got it from that Sea Hag don't you remember.
Wizard: Can I Cast This Spell?