TR - Trim: Cut lines by first selected lines (Enter)
EX - Extend: line to first selected line (Enter)
O - Offset: specify distance, object and side
TOOLBAR - will display basic tools
XL - Construction Lines
Enter Enter or Space-Bar Space-Bar will repeat command
DimScale will change dimension (DimAligned) font size
LA - Layers panel
PR - Properties panel
OV - Overkill can remove duplicate lines etc.