One of the big distinctions that appears between OSR gaming and late 2E/3E+ versions is the fundamental view of magic... OSR gaming leaves magic intentionally vague and mysterious, while later versions endeavor to account for the nature and function of magic in its various forms. This rears its head in the ugliest ways in terms of the specific costs of mass-producing magical items. I'm far more interested in magic that doesn't work in any sort of consistent rule that we can determine... for example:
A dwarven master weaponsmith, on the evening he learned that his son had died in battle, went into his shop in absolute silence, pouring his sorrow into his work - releasing his anguish with each hammer blow, cooling the metal with his fierce tears. Two days later, he returned home with a hammer that he had named for his son, a war hammer +2 with limited empathy and lawful alignment. This is an OSR weapon.
This is better than the 3E+ approach to saving up 50,000 gold coins and a crushing a gemstone valued at at least 10,00 gold. The dwarf cannot re-create the circumstance of this smithing, and he cannot mass produce such weapons (unless he has a whole bunch of sons he can sacrifice to make it happen). Each magical item becomes unique in its story, even if it's not unique in its abilities.
In the same vein, as I write spell descriptions, I'm intentionally excising language that limits or inhibits the spell. For example, in hold person, I particularly like the phrase 'human like creature' as a potential target for the spell, and I'd prefer to end there rather than listing creatures that can be affected. For example, is a mermaid 'human like'? What about a dragon that has used polymorph to appear as an elf? I'd rather leave such situations to the GM to determine... what makes something 'human like'? Physical appearance? In that case, I'd argue yes in both cases - and I think that in general, GMs should be liberal in their flexibility with the application of spells. The more you describe a spell in minute detail, the more you limit how and where it can be used. I plan to avoid this.