Racks
Solid, dependable and trustworthy a rack to carry your luggage when riding can still trump new-fangled, rackless solutions.
If you want to carry items of a decent weight a rear pannier rack is a sensible way to go. And if you're aiming to carry something lighter, but no less baulky a front rack is also an option.
Just be sure your bike has the requisite mounts, so you can screw your chosen rack to the frame.