Here is something simple but worth it. Osnap - Parallel. This Osnap allows you to draw a new line or object parallel to a reference object. You start the line command, and then using the Parallel Osnap hover over the reference line. You will see a symbol looking like this "//" over the line. It will disapear as you move off, but once you are lined up parallel with the reference line and your new line, the symbol will reappear and you can draw your line parallel. Simple but effective! Enjoy!