Kevin E. Vaughn shared a tip for setting AutoCAD objects — especially blocks — to Bylayer.
“When creating blocks, always use layer 0 to create the blocks in. Use the Setbylayer command to change everything to the current layers, including all blocks.”
Notes from Cadalyst tip reviewer Brian Benton: It is good practice to have all of your objects set to Bylayer. If you don’t, you lose the ability to manage the display settings of your objects in a viewport. If an object’s properties (such as color or linetype) are set to a specific color or linetype, that object will always be displayed with that color or linetype. This is important because you never know what your future drawings may need or how other users may need to display your linework.