COPY or MOVE relative to DUCS
When working in 3D it can often be easier to create new objects on the WCS, then manipulate them into position afterwards. Of course this still requires a bit of work to position and align your new object to existing ones in your model. However by using some LISP and levering of the properties of the INSERT command you can make this rather effortless.
CopyMoveDUCS.lsp allows you to COPY and MOVE objects relative to the DUCS.