Getting Past the "Rough Mix" Stage

Normally, I'm the lighting guy, but about once a month I get to play around on the sound board. For me, this feels like going back to my roots. My fascination with all things a/v started when I was old enough to follow my dad around while he was running audio for our family's church. More recently, I have gotten to run audio with a team of people for a contemporary worship setting. One thing has remained constant until now - there has normally been ample time to do a proper soundcheck.

I am used to multiple hours at one time being devoted to perfecting the mix. I had time to go through every channel and experiment with multiple settings of eq, compression, effects and other things. I went through until I found exactly what I wanted for that one channel and moved to the next. When I finally got each input to sound exactly like I wanted it to, I moved on to blending and sweetening. By the end of a 3 hour rehearsal, I usually had a sound that I was pleased with. I figure that most people generally follow the same method.

Now, I get less time, more complicated setups and inputs that I'm not well versed in mixing. An average Sunday that I run can consist of (on average) a 25-piece orchestra, 75-voice choir, another 12-piece vocal group. At the high end, I could have 40 or 45 inputs. That is way more than I was used to in previous settings. At most there is 2 hours of useful practice that I could do any mixing. Of that, only the last 45 minutes are with the entire group together. The biggest issue is in the orchestra. I mix instruments ranging from bassoons to cellos to a harp. Quite frankly, I have not been completely happy with a mix I've created in over 2 years.

This is my current strategy to finding an acceptable mix. My base was made from a generic setup from our normal sound dude. From there, I reset everything to a flat eq and no compression. (I didn't do this because I hate what I hear every Sunday. Our regular sound dude great. I just like to put my own signature on the mix.) On the first Sunday I ran the audio, I did a lot of generic eq'ing. From then on, it's been rough. I've only gotten to get one or two mics per rehearsal sounding the way I want.

They sound great for that rehearsal, but the inevitably change a little in placement or some other minute factor that leaves me wanting the sound I just had, not the one I have now. It is just a constant struggle to get an acceptable mix and I only end up with what I would consider a rough mix.

My question is....How do I solve the never-ending rough mix? Or should I be happy with where I am? (The latter would be extremely difficult for me personally because I always want to improve my mix.) Comment with your ideas...please :)