How can I duplicate a mirrored version of something like a horn?

Is it possible to duplicate an object in a mirrored version of itself? ie if I make a left horn pointing inward, can I duplicate an mirrored version for the right that also points inward?

I want these objects to be unconnected

Use mirror modifier?

Or duplicate (Shift+D) and mirror across the appropriate axis (Ctrl+M / X for x axis)

Won’t that give me 1 connected object instead of a new separate object that is left instead of right and visa versa?

I tried mirroring on the x-axis and it gives me the object upside down? I also tried making a duplicate and scaling it on the x-axis by -1, but that is also giving me and upside down version. Where is this going wrong?

Sounds like you have a rotation on your object. Apply the rotation to the object (Ctrl+A) before mirroring

Please ALWAYS attach or post a link to your blend file so we don’t have to use purely our imagination when figuring out your scene

Yep that did the trick. It was the rotation. Thanks.

Also it’s better to mirror in edit mode and then select all, and hit ctrl+n, as it not only mirrors the object on an axis but also flips the normals.