I avoided woven bags for years because every one I tried on looked like it belonged to someone else, someone with a holiday I hadn't had and a lunch I hadn't been invited to. What changed was a straw tote I bought for one specific trip and then kept using for months afterwards, long after the holiday photos stopped being relevant. It turned out the bag had nothing to do with the holiday at all. It just worked.
If you're starting from nothing, I'd get a mid sized tote with a flat base and two handles, nothing too slouchy, nothing with a drawstring you have to fight with at a till. A basic shape in a natural straw or raffia does more jobs than anything embellished or oddly structured. You want something that can hold a water bottle, a cardigan and a paperback without the sides bowing out like they're giving way, because cheap ones do exactly that.
The difference between a good one and a disappointing one shows up fastest at the handles. On the bad ones they're stapled or glued into a seam that starts fraying within a month. On a decent one they're woven right through the body of the bag or stitched into a proper fabric lining, so there's actual structure holding the weight rather than a bit of hope. The weave itself matters too. Raffia is soft and a bit fragile, lovely to look at, less lovely in the rain. Seagrass and a tighter palm weave hold their shape far better and don't go limp the first time you overfill them. Check the lining as well, a cotton lining with an actual zip or clasp beats an open straw bag every time you're on a crowded train trying to find your card.
Hardware is where the cheap ones give themselves away. Flimsy clasps that don't quite meet, metal rings that have already gone a bit dull before you've left the shop. On a well made bag the hardware feels like it was chosen to match the weight of the thing, solid without being heavy, and the finish inside the weave is neat rather than full of loose ends poking through.
These suit late spring through to early autumn properly, anything from a lunch outdoors to a weekend away, but I've also carried mine through a mild October without feeling like I was clinging to summer past its welcome. They're not an evening bag and they're not trying to be. What makes a good one a pleasure, though, is the first time you sling it over your shoulder and the handles sit flat against your coat instead of digging in, no matter what you've crammed inside.