The question I get most about relaxed fit blazers is whether they just look like you've borrowed something too big from a partner's side of the wardrobe, and the answer is no, but only if the shoulders land in the right place. A relaxed blazer should feel roomy through the body, not through the shoulder seam. The moment that seam droops past where your actual shoulder ends, you've gone from deliberately loose to accidentally enormous, and those are very different messages to be sending before nine in the morning.
Getting the fit right is mostly about ignoring the old rules and trusting your reflection instead. Shoulder seam sits at the shoulder, sleeves can be pushed or rolled, and the body skims rather than clings, that's the whole job. Watch the back for pooling fabric below the collar, that's a sign you've sized up too far rather than chosen a genuinely relaxed cut, there's a difference between the two even though shops rarely bother explaining it. Watch the front too, if it gapes open across the chest when you move your arms forward, as if reaching for something on a train, that's not relaxed, that's just too big, and no amount of confident walking fixes it. I spent a while thinking I had broad shoulders until I realised I'd just bought three blazers in a row a size too large and blamed my body for what was actually a tailoring problem.
Where it gets tricky is pairing it with anything else that's also oversized. A relaxed blazer over a baggy shirt and wide trousers can tip from considered into costume, especially if everything's the same mid tone, at which point you've essentially dressed as a tent having a meeting with another tent. It wants one fitted element somewhere, a narrower trouser, a close top underneath, something that tells the eye where your body actually is, otherwise the whole outfit reads as fabric rather than a person.
The honest limits are worth saying plainly. If you need structure for a specific formal setting, a presentation, an interview where sharpness reads as competence, this isn't that blazer, the soft shoulder and loose drape don't do the stand up straight job that a fitted blazer does. It's also not forgiving if you're petite and buy true to a size rather than sizing down, the proportions can swallow you whole in a way that reads as wearing a coat rather than a jacket. For everyday wear though, the kind where you want to look like you've made an effort without looking like you tried, it's one of the easier pieces to feel good in by lunchtime.
