1. CLOSE NON-SESSION WAVES A LOT - If you tend to do a lot of takes of any particular instrument, where you just record over the same spot until you get it right, then after you finally get a whole track down (a vocal, for example), select "Close All Non-Session Waveforms" and when it asks you if you want to save whatever tracks are NOT in your multitrack session, choose "No To All." This makes eventually saving the session a lot simpler, and it makes my computer run faster...it also seems to decrease the odds of a meltdown in mid-session.
2. SELECT 32 BIT ON EVERY OPTION YOU CAN - This is actually a very big deal to me now. I used to record and mix everything in 16 bit, b/c for some reason, that's how my first version of CEP was setup to record by default, and I didn't know any better. I won't get into it too much now, but the WAY CEP works is in 32 bit, no matter what you've got your options set to, so if your options are set to record and mix in 16 bit, then CEP has to convert the file 2 or 3 times for each "thing" you do to it...like if you add reverb to a vocal, it INTERNALLY converts your 16 bit file to a 32 bit file, then adds the reverb, then converts it BACK to a 16 bit file. The conversions involve a "dithering" process that I know almost nothing about, but I know that the cumulative effect of this is to dull the overall sound (attenuates the highs), and there are some waves that I might run through 8-10 processes (compression, EQ, reverb, chorus, etc.)...so w/o even knowing it, I was basically forcing my tracks to undergo 20 unnecessary conversions before they ever got mixed down in a final file. It was this forum that straightened me out, and my mixes IMMEDIATELY improved about 10 fold...Man, I felt like a dufus. THAT'S SOMETHING I WISH I'D KNOWN.
So go into your settings RIGHT NOW and go through each panel, and everywhere you see an option to select between 16bit or 32 bit, select 32 bit...some examples would be "open files as 32 bit" or "mixdown 32 bit" or "submix 32 bit"...every damned one you can find.
The ONLY time you should use 16bit is when you've finally got your final mix that you want to burn to CD...at that point, you have to convert it to 16bit in order to burn it to CD.
Those were the 2 things that probably tripped me up the most.