I recently got a new iPhone and need help transferring my messages. I’d like to ensure I get all conversations from my old device moved over to the new one without losing anything. Does anyone have advice on the best way to do this or any issues to watch out for?
Oh boy, transferring messages to a new iPhone—it’s a modern rite of passage, huh? Okay, so here’s the thing, if you’ve got iCloud backups enabled, you’re probably halfway there. Go to your old iPhone, head to Settings > [Your Name] > iCloud, and then make sure Messages is toggled ON. Important: Make absolutely sure you’ve done a recent iCloud backup. Go to Settings > iCloud Backup > Back Up Now—don’t skip this, or you might be crying over lost texts.
Once that’s done, grab your shiny new iPhone, start the setup process, and when it gets to the Apps & Data screen, choose to restore from iCloud Backup. Log in, pick your most recent backup, and all your messages should magically appear after a little patience (or a lot of waiting, depending on your Wi-Fi speed).
BTW, if you’re like, “Nah, screw iCloud,” and don’t want to use it, there’s another way—connect both phones to a computer with a Lightning cable and use Finder (on Mac) or iTunes (on Windows). Do a full backup of your old phone (click the ‘Encrypt Backup’ option to save all that sweet, sweet data like messages), and then restore that backup onto your new phone.
Oh, and if you’re on Android, sorry—this thread ain’t for you. 
You know, @cacadordeestrelas’ suggestion about using iCloud or iTunes is solid, but here’s a wild card—have you tried Apple’s Quick Start feature? Honestly, it’s way less hassle than messing around with backups and restores. Place your old iPhone near your new one, and they’ll start doing their magic handshake (well, not literally). You just follow the prompts. It clones the essentials—including Messages—directly over. No middleman, no backup stress.
Here’s where I disagree a tiny bit with the backup-only approach—sometimes those full iCloud restores can be finicky, like the Wi-Fi gods need to be merciful that day. Quick Start avoids waiting for the backup to finish uploading and downloading. Boom, instant(ish) result. But yeah, you still need both devices on Wi-Fi and their respective batteries juiced up (please don’t try this on 10% battery unless you like living on the edge).
FYI, though, if you’ve got a ton of stuff saved (pics, apps, etc.), that whole process might take a minute. But if all you care about is Messages? It’s kind of chef’s kiss-level easy. Sleek, simple, less chance of user-error—you’d only mess it up if you warped into a pocket dimension halfway through.