Low rise jeans are the thing you reach for when you're wearing a cropped jumper or a short jacket and you actually want the waistband to disappear rather than sit there as a visible line under the fabric. Anything with a fitted top half and a bit of midriff on show, this is the jean that makes that look work, because the proportions are already right before you've put anything else on.
They're not the right choice for sitting through a long day at a desk, or for anything involving a lot of bending and reaching, because the rise is doing exactly what it says and there's very little room to move before you're hoiking them up every ten minutes. They're also not kind if you're someone who carries anything in your coat pocket, since there's nowhere for a phone to go that doesn't end up digging in. Where they do earn a place is in the evening and the in between seasons, spring into early summer especially, when you're layering a vest or a fitted tee underneath something cropped and you want the whole outfit to read as one line rather than two halves fighting each other. A bit of warm weather helps too, because bare ankles and a low rise balance each other out in a way that feels deliberate rather than accidental.
On colour, a mid blue wash is the easiest version to live with, it goes under more tops without you having to think about it, and it ages better than anything too light or too dark, which both show wear in places you'd rather they didn't. A worn in, slightly faded indigo is lovely if you can find it, it looks like it's already had a life rather than like it's trying to convince you it has. Black can look sharp but shows every crease at the front in a way that mid blue simply doesn't. What separates a good pair from a sad one is mostly in the denim itself, something with a bit of weight and a small amount of stretch holds its shape through a night out instead of bagging at the knee by nine o'clock, and the button and zip should feel solid, not like they'll work loose after a few washes. Check the inside seams too, a cheap pair frays there first, long before the outside shows anything.
Put a pair on under a jumper you already own and the whole thing suddenly looks like it was planned.