Zen and the art of home theatre adjustments

All things being equal what is the general principle involved in adjusting home theatre parameters when controls on two pieces of equipment are redundant.
For instance, do you get a better picture if you adjust the color saturation using the video control on the Sony 9000ES DVD player or if you adjust the same parameter using the video control on your Mitsubishi big screen. Do you do a combination of both or does one piece of equipment get adjusted first. Is there a hierarchy to the order?
Same thing for sound...turn up the gain on the back of the subwoofer or do the same adjustment using the gain control on the processor.
What is the choice, from a theoretical perspective, that yields the best sound or picture. Is there a "general principle" involved or am I forever doomed to fiddle with these parameters forever in endless combinations and permutations.
The flip side of which is how much time in your viewing/listening sessions is taken up in adjustments of parameters. Is there any home theatre set-up that automatically remembers your complete last set of adjustments (both audio and video) as it relates to the various source materials that you've previously selected and "adjusted" for.

Otherwise, like me, do you all listen/watch with remote(s) clutched firmly in hand(s)?
Ah you bring up some very pertinent and thought provoking questions. Indeed there are LOTS of paramaters and adjstments/tweeks to consider in a properly set up HT these days...and the difficulties keep growing as the system complexities do! These questions and their practical answers are the reasons that "leaving it up to the professional" is a very good, and even recommended option to consider!
Knowing "what does what", and the "why's", and "how much" and "for what reasons" is something you can only really nail down by having LOTS OF EXPERIENCE, time, and knowledge behind you. Ulitmately however, if one is interested in doing it themselves, as most end up doing (to only mediocre results on average sadly), you'll have to do your research, tinker lots on your own, and be prepared to make it a hobby! If that's acceptable and desireable for you, the rewards will end up being very much worth it!
Ultimately, the controls, settings, gains, set-up paramaters and such for a complex audio/visual system need to yeild PROPER BALANCE. BALANCE is the key, as with anything ultimately. A quick suggestion would be to set everything as close to a "relative-middle" as possible, and adjust from there if applicable. My experience suggests however that it's generally "promoted" by many experienced audio reviewers even, that you set the subwoofer volume control somewhere in the middle, and adjust from the processors level control for that application. Your results maybe different, depending on equipment used of course. For Video players and displays, I think the general trend is to let the player stay "flat", and adjust the video displays controls, which are likey more accuract, "fine tuneable", and involved probably. I've heard most professionals say they calibrate everything from the video display, and do miniman tweeking with the video source. Again, equipment might vary for best results.
As for proper level controls in general, with either video or audio, I find that if you set things properly from the beginning(most don't, nor will things ever be), you don't need to go "up and down" on the settings or controls! This is often a problem in most systems where the sub is up to loud, the system is too bright, the video display has too much contrast or brightness level, etc, etc! What you have there is a situation where there's limited dynamic range in the applicable display or playback system, simply because some portion of the audio/video spectrum is off balance, and tilted towards "high" all the time!...never allowing for delicate or low level playback. In the case of an audio system, where say the bass is too loud in proportion, you never get anything but constant loud booming, distorted, over-exagerated and dominent bass!...never balanced, articulate, even, and well integrated bass, that keeps the dynamic range in perspective and "wide-reaching"! The Same is to be said with video dispays where the contrast, say, is up too high, and everything ALWAYS LOOKS bright!..never suttle. There's no dynamic range here...and there's no middle ground.
Now as for gain matching levels and such, you don't want to loose dynamics with mismatched levels in an audio system. I can think of instances where getting enough gain to the amplifier is critical for proper dyanamic yield. This may however have more to do with impedence matching than anything else. Still, I have gotten better results with some equipment by, yes, adjusting things different than the norm...so experience and trial and error come in to play here.
You might want to consult old articles about such topics of interest, and recommendations are often expressed. Also, if you ABOVE ALL, consult your users manuals for your equipment, they often suggest the best mothod to use for best results with their gear!...that is a no loose recommendation right there.
Good luck
I'm a tweaker myself. I'd recommend picking up a decent video calibration DVD like the AVIA home theater disc and following the sequence they lay out. There is a "better" way of sequencing adjustments so that you end up with a decent result.

Based on the fact that you probably have multiple video sources, I typically leave the sources on the most "default" settings possible and tweak the monitor--most monitors, for example, have significant red push. If you fix that by calibrating your DVD player, you'll still have the red pushed when watching DSS.

If you have a really high end video system, getting a certified calibrator may well be worth it. There are a range of settings for most monitors that consumers don't routinely have access too--mainly because you can damage your set if you don't know what you are doing. If you are careful, do so research on www.avsforum.com and poke around on the web--you can find loads of set-specific information, including how to get access to nonstandard controls.
I agree with Edesilva, avsforum.com is as good as it gets fo info. on this type of stuff. I always set my sub at the processor and fine tune output if need be at the sub. The T.V. should also be the main set point, not the dvd player for video.
Thanks for everyones input. Great advice from foreverhifi. It really helps to know to set the DVD to neutral and adjust from the set. I wonder if the principle is to adjust the downstream components and leave the upstream ones at neutral. Twenty years from now I predict the home theatre will readjust itself continually in real time to reflect how we, on first listening, previously corrected the set-up to reflect our preferences (i.e. surround output, bass output, picture "sharpness" etc)for the various software that we're playing. Nirvana