Keep the code simple — the tag is tiny
A gift tag leaves very little room to work with, so the destination link should be short — a clean URL rather than a long path loaded with tracking parameters. Fewer characters means fewer modules in the QR pattern, and fewer modules means the code is far more forgiving when it's printed small. A long, complicated link crammed onto a tiny tag turns into a dense grid that's genuinely harder to scan.
A plain, short link or a simple shortened URL works better here than pasting in a raw cloud-storage address. Stick to a clean, high-contrast style rather than an intricate dot pattern that could soften further at very small print sizes — simplicity is doing real work at this scale, not just a design preference.
Paper tags get creased — plan for it
Paper gift tags get folded, stuffed into gift bags, and generally handled more roughly than a printed page ever is — creased corners and the occasional small tear are normal by the time they reach the recipient. Leave a generous quiet-zone margin around the code so a crease near the edge doesn't cut into the actual pattern, and avoid any planned fold line running straight through the printed code if the tag itself folds in half.
If you're printing at home, a slightly heavier cardstock resists creasing better than thin paper. If the tag attaches with string or ribbon through a punched hole, make sure the hole and the knot sit well clear of the code rather than overlapping it.
Sizing for a close-up, handheld scan
Unlike a poster or a yard sign, this code gets scanned inches from someone's face while they're holding the gift, so it can be genuinely small — but "small" here still means roughly 2-3cm across, not something the size of a fingernail. Go smaller than that and a phone camera has to hunt to focus at close range, which defeats the whole point of the tag being quick and effortless.
Test-print it and scan it yourself with a phone before it goes on any actual gifts, especially if you're printing a batch of tags for a wedding or a party. A code that scans easily sitting on your desk should scan just as easily the moment someone unwraps the present.