There’s some useful info out there:
Dave Dixon has some really useful info on Speeding Up Civil 3D. I suspect these tips will work for vanilla AutoCAD as well.
Ellen Finkelstein on Clipping Blocks
Justin Zeimba on the downsides of ClearType
Donnie Gladfelter shows us how to Create Blocks with Multiple Insertion Points
Shaan Hurley links hatches to tables
Aleksandr Smirnov has a nice collection of LISP routines
