When recording audio.
 
Set all gain and faders at unity and leave them there. Adjusting any of them will give you false meter readings. If your input level is too hot lower it at the source or before it gets to your A/D converters. This is very important to understand. Sonar has no control over input levels. It can adjust them only after they have been recorded to the hard disk. Use the meters in Sonar to monitor the levels while recording. 
 
There is also a preview mode for recording that will draw the waveform as it is being streamed. It is also known as Confidence Recording.

How many are using screen sets? It one of the new features I picked up on right away. 
I just use the defaults 1-2-and 5. Each gives you a different view, 5 is the Console view for example.  
2 has the synth rack etc. So I mostly work in # 1 but will switch to #2 when I want to insert a synth and to #5 for mixing. There are other ways to navigate but screen sets work great for me. 
They seem to be kept with each project and you can customize and save them but I've yet to bother. The defaults are fine by me. 

Screen sets are a recent feature that was included in X1 and above. To follow on Johnny's post above. You can create your own and save that set under a new empty project. If you wish to import those into a new project make sure you have allow multiple projects open and open the project with your own screen sets. It then becomes a matter of importing them in to the new project. You do this via the screen set control bar module.
 
If you use the "normal" template as a starting project import them into it. 

John, just to be clear...you are saying that during tracking, the user should only adjust the input device or interface for levels and NOT Sonar, but the user should watch Sonar meters for individual tracks for accurate levels, which from prior posts, I gleaned, should be around -6dB. And of course keep in mind that the interface should at no time go in the red on it's meters.
 
When I track in Sonar 7PE (been awhile) I think I remember the wave forms being drawn in real time...is this what you are speaking to with regards to Confidence Recording.
 
I hope to soon be tracking in X3PE, should I expect the same real time wave form drawing, or is there something I should be aware of in terms of selecting a view or something?
 
Thanks John.

TremoJem Yes.