If you've just spent forever tweaking an effect (audio or video) on one clip on the timeline, and you need to apply the same effect to another clip, just copy the one you worked on, right click on the other clip, and select "paste attributes."
Lots faster than manually tweaking the effect for each clip.
When I'm editing I like to run 2 audio channels. I pan ch. 1 all the way left, and ch2 all the way right. Then when I'm dropping clips in, I drag to either v1 or v2 depending on what sound input I need.
Oh, and reset your keymap so that E and R are in/out instead of I and O. Puts your hand right near the other commonly used keyboard shortcuts, so you can edit with one hand on the mouse and one on the keyboard.