Why English-style names sound real
Real English place names are made of a few dozen recurring parts, and readers know them without realising. A name ending in -thorpe, -by or -wick sounds like a village because thousands of real villages end that way. Add a second word the way real places do, such as a church (St Giles), a position (Lower, Nether, Great), a river (-on-the-Wold) or a market (Chipping, Market), and the name gains a history.
Our Naming Library page on English place-name elements explains what each part originally meant, so you can build names that describe the place: a -combe sits in a valley, a -hithe is a landing place on a river or coast.
Naming a whole map
Places in the same region should sound related. Pick two or three endings for each region and reuse them, as real counties do: a coast full of -hithe and -cove towns, a north of -gard and -heim. Then let the odd name break the pattern to show history, like an elven ruin in human lands or a dwarven name on a hill fort.
Vary the length too. A map where every town has four syllables is hard to read; mix short names like Ashscar with longer ones like Dunbourne-on-the-Wold.