Well I dont know what kind of details you’re trying to model on this cylinder. But theres a few things you can do. You can make a plane, and use an array modifier, and then bend, and model the details on there. There will be a bit of a distortion, but depending on what you’re modeling thats fine. You might also be interested in the shrinkwrap modifier, which would allow you to project a model onto another model.
You could also model the details separately, and then duplicate them around the cylinder.
Unless you’re talking about UV unwrapping? In which case, in edit mode. select the faces for the loop of the cylinder. press U to bring up the unwrap menu click on “reset” and then bring up the unwrap menu again, and click on “follow active quads” In the UV editor, you’ll see all your looped faces connected to eachother in a nice neat fashion, that you can scale, rotate, and move to your hearts desire.
But like I said, without more info, its hard to recommend a most efficient course of action.