A good bowl should feel slightly too heavy for its size, and if it doesn't, you'll resent it within a month. There's something about the weight settling in your palm that makes cereal taste better, I don't have a scientific reason for this, I just know the flimsy ones always end up as the bowl nobody chooses from the cupboard.
Deep bowls make sense in kitchens where soup and pasta and rice actually happen on a weeknight, not just on the weekend when you've got the energy to pretend you're someone who meal plans. Shallow, wide ones suit a house that eats a lot of salads or does breakfast in stages, cereal, then fruit, then regret. If you've got a small kitchen with narrow cabinets, stick to bowls that nest cleanly, because a set that won't stack is a set that will live in a precarious tower until it isn't anymore.
Where bowls fall short is anywhere you need real durability without babying them. If you've got a toddler lobbing things from a high chair, or a kitchen that doubles as the dog's feeding station, skip the thin ceramic and get something heavier or go melamine for that specific job. Beautiful glaze does nothing for you the first time it meets a tile floor at speed.
For sizing, measure what you actually eat out of now, not what looks right stacked in a cabinet photo. A cereal bowl under five inches wide will feel stingy the second you add milk, and anything much past seven inches starts behaving like a serving dish whether you meant it to or not. The mistake people make most is buying a full matching set in one size, when really you want two sizes you'll use differently, a smaller one for the everyday stuff and a bigger one for the nights you actually cook.
In a shop, run a thumb around the rim before anything else. If it's rough or uneven, that's not a quirky handmade detail, that's a bowl that'll chip your spoon in a year. Check the base too, a wide, flat foot sits steadier on a table than a narrow one, which tends to wobble the second you lean on it with a fork. On delivery, tap two together gently, you want a clean ring, not a dull thud, the thud usually means a hairline crack you won't see until it's full of soup.
Buy the ones that feel good in your hand before the ones that look good on a shelf.