Lifting weights can certainly help, though people who focus on the bench press and neglect their upper back muscles may find that their posture actually gets worse, rather than improves.

(Yet it's interesting, though hardly relevant for most of the population, that bulky upper back muscles can also look like bad posture. In extreme cases, a very well-developed upper back can even result in a mild hunchbacked appearance.)

More to the point, those posture correction devices actually work. The shoulder straps are okay. The Chinese sell a slim metal device -- I've never seen it in the USA -- that fits around your neck and prevents you from looking down and slouching over. That damn thing is like magic. A few two-hour sessions over a few days can markedly improve your posture.

Having a hard time visualizing this. Is it possible to get one from like AliExpress?

Another heuristic I use is you should not get a glance of your feet when standing tall. It's not like a device but it's free and you always have with you, you just need to remember to check.