A couple of things I have recently discovered:
You know how SLOW it is, panning around a floor plan (by holding the mouse button down and dragging). It's so bad that the image completely disappears, and re-appears 10 seconds later, hopefully in the spot where you want it. If not you haver to go through the same tedious precess again.
Well, this whole "pan-by-dragging" process appears to be much much quicker in a 3D view.
So here's the tip:
Go to you 3D view, then go to the dynamic view (F8) and orientate the view to top. It effectivly gives you a plan view. Now you can pan around a plan much quicker. Bingo!
And the other tip, if you orientate the 3d view to an elevation, you can effectivly draw 3D pipes and ducts from a section view, something you can't do from a normal section.
Hope it helps....