My first set came in a box with twelve pieces and a cartoon chip on the rim before I'd even run the dishwasher once. The lesson there was simple: a set is only as good as its weakest plate, and that stack of bread plates I never used didn't make up for dinner plates that chipped by month two.
If you own nothing yet, start smaller than you think. A four person set, dinner plate, salad plate, bowl, covers most weeknights and most of what guests need too. You can always add mugs or a serving platter later, but buying the sixteen piece set before you know how you actually eat is how you end up with eight soup bowls living in the back of a cabinet for a decade.
The difference between a good set and a disappointing one shows up at the edges, literally. Pick one up and run a finger along the rim. A well made plate has a glaze that's even all the way around, no thin spots, no rough patches where it pooled. Stoneware and porcelain both hold up fine, but the weight should feel deliberate, not like they skimped on the clay to hit a price point. Stack a few together and listen. A dull, solid knock means a dense piece that'll survive a move. A thin, hollow clink is the sound of something that chips the first time it meets a countertop at the wrong angle.
Where it goes wrong is matching plain, heavy stoneware with delicate glassware or very formal flatware. It just looks like two different dinner parties collided. Keep the weight and the formality roughly in the same lane, rustic with rustic, finer with finer, and the table stops arguing with itself.
What actually tells you if a set was worth it is a full year, not the first dinner party. Does it survive the dishwasher without the glaze going cloudy. Does it survive a move packed in newspaper in a cardboard box, or does half of it arrive as gravel. Does it survive the particular violence of a toddler deciding a bowl is also a drum. The sets that make it through all three without looking tired are the ones worth repeating.
Before I buy, I ask myself one thing standing there with a plate in each hand: if I dropped this on tile right now, would I be annoyed, or would I be replacing the whole set by spring.