The phonetic signature of each people
Dwarves: hard clusters, short vowels, stone and metal consonants (Brom, Dwal, Thra). Elves: soft sibilants and liquid endings (Ael, Syl, -iel, -wyn). Orcs: guttural monosyllables (Gro, Thok, Brak). Halflings: friendly b- and p- onsets with doubled sounds (Bilbo-style). Tieflings: infernal latinate flourishes (Mordai, Nemeia). Humans: whatever their culture borrows — widest range.
Epithets and clan names add depth
One personal name is a stranger; a name plus a marker is a person. Dwarves carry clan names (Brom Ironhollow), elves often use a place or deed epithet (Sylwen of the Fen), orcs earn titles (Thok the Unbowed). Add one marker to important NPCs and your world doubles in perceived depth.
Party consistency without sameness
The party's names should share zero initial letters (two 'K' names collide at the table) and vary in length, while each name stays true to its race's phonetics. Read the initiative order aloud as a test: five distinct sounds means five distinct characters.
DM batch-naming for NPCs
Sessions generate NPC needs faster than prep fills them. Batch-generate twelve race-appropriate names before session, keep the list visible, and cross names off as the table meets them. The discipline upgrade: note each used name with one trait — 'Thok: owes money in Waterdeep' — and your world self-writes.
When to break the rules
Every table has the gnome barbarian named Steve. That joke earns its place once per campaign; after that, phonetic consistency is what makes the exceptions funny. Break the pattern deliberately, never accidentally.