Relaxed trousers have a reputation for being the thing you reach for when you've given up, and for a while I believed that too. I spent a good two years thinking "relaxed" was code for shapeless, until I tried a pair with an actual waistband and a proper break at the ankle and realised the problem was never the category, it was the cut I'd been sold.
The thing to watch is what you put them with. A relaxed leg over a boxy jumper just reads as volume on volume, and you end up looking like you're wearing a duvet with pockets. They want something with a line to it, a fitted top, a jacket with structure, boots rather than trainers if you want the whole thing to hold together rather than puddle. What tells you a pair is worth keeping is in the fabric before anything else, a heavier cotton or a proper wool blend that drapes rather than clings, with enough weight that the leg swings instead of flapping. Check the waistband construction too, a decent one has proper facing and doesn't roll after a wash, and the hardware matters more than people admit, a button that's actually sewn through rather than glued will still be there in a year. A cheap version goes thin at the knee and the crease sets in wrong, so instead of one clean fold at the front you get a general crumple that no amount of ironing fixes, and that's the bit nobody tells you when they're selling you the idea of comfort.
They are not the answer for anything that needs a sharp line, so if you're walking into a meeting where you need to look like you mean business, a tailored trouser will do more for you in ten seconds than a relaxed one will all day, however good the fabric. They're also no good wet weather friend, a loose hem drags through puddles and holds the damp in a way a cropped leg never does. Where they earn their place is anywhere you need to sit for long periods and still look like you tried, a long train journey, a lunch that runs on, a weekend that involves a lot of standing about with a drink in your hand. Spring and early autumn suit them best, when you want something that isn't clinging but still looks deliberate rather than defeated. For a first pair, go for a mid grey rather than black, it hides less and flatters more, and it won't fade into looking tired the way black cotton does after a dozen washes.