It doesn’t get much more straightforward than this! Available on the Autodesk App Store, ConstructionLines is an app that helps you create a construction line of infinite length and gives you the ability to select Xrefs and blocks, too.
Examples of commands include:
Take a look at ConstructionLines on the Autodesk App store (and it’s free!)
Check out the entire series for more AutoCAD apps available on the Autodesk App Store.
XLINE does pretty much the same thing.