Li Shenron
Legend
Forgetting changing individual spells, how would you improve spells in general? In terms of things like formatting, classification, and content.
(Not asking about individual spell changes or fixes at this time).
Bear in mind, we’re not changing the underlying system. This isn’t about alternate spell systems. Assume you’ve been tasked to take the existing spell lists and rewrite them. What do you do?
That's a difficult question...
I wish saving throws were more spread around instead of being concentrated on Dex/Con/Wis. For example Str saves for everything that impedes movement (incl. paralysis and petrification), Int saves for everything that confuses reasoning (incl. Illusions) and Cha saves for everything that pushes you mentally to unwanted actions. Instead of Int/Str/Cha saves, many spells allows checks, but then why not making either all saves or all checks? This one ship has sailed however.
I wish more spells were scalable.
I wish rituals were more about not having to prepare certain spells, than casting them for free.
I wish there were spells with a larger area but a cap on how many creatures are affected.
I wish to put an end to ridicule of focus components. Make any object a valid focus for everyone, perhaps with the requirement of having to attune (so you can't just pick up a pebble on the spot). It's ridiculous that people think "with this new book, now your character can also use a <insert specific object here> as focus". That's just a cosmetic choice.
Generally speaking, I wish for clear and simple requirements for spell components. Say that you either need a free hand without exception, or you don't need it. It's insulting to hear player explaining how they juggle objects or how "I have put a strap on my mace" just to circumvent the free hand requirement. Either enforce it for real, or ignore it completely.
As for presentation the obvious improvement is one-line descriptions in the spell list. It has been asked since the first printing of the PHB but WotC never delivered. 3ed one-liners were very useful especially for those new to playing a spellcasting class.