I don't talk about Aperture adjustments much but I had an Aperture user email me about two specific Aperture adjustments and some issues that he was having. What I suggested to him was actually a work-flow solution. Well a work-flow solution and a photographic philosophy solution as well. He was a Nikon shooter but this tip applies to a way to approach things for just about any kind of shooter. In fact it maybe something you should think about even if you don't use Aperture.
Remember the old days when film had one or maybe two "white balance" settings? Tungsten or Daylight. You loaded up and shot. If you were a color negative shooter - don't worry your lab will get it right, especially if you have a close relationship and they know how you like your color to look. If you were a slide shooter you filtered for the situation. Nice and simple. I suggest you take a similar approach with digital white balance. Not exactly but similar. Like most things in the automatic digital world - there are a lot of automated things that I consider specialized tools that have somehow found their way into the default way of doing things. Auto white balance is one of them - it causes more trouble than it is worth in a lot of situations. Most actually.
Like most Nikon shooters - this Aperture user did not like the default rendering of his NEF files in Aperture - white balance was one issue. Here is the solution. Don't use auto white balance, especially if you shoot RAW. Pick a white balance preset - either daylight or cloudy or whatever. I actually use the little kelvin numbers because that is the language I am so used to. Pick it based on how you want your scene rendered and go with it. Don't change it until your scene changes.
Doing this does two things. The first is that it gives you a WB that you might like - in my case I usually shoot in daylight WB and happen to be in either warm or cool light depending on the mood I am going for. If I want to warm it up a bit I crank the WB up in Kelvin numbers if I want to cool it down I do the opposite. Fantastic my JPEGS look like I want them to look right out of the camera.
The second and more important thing it does for you is gives you a series of images that have the same exact color temps and color renderings. If you shoot RAW this situation is far far better than having a series of images that are all over the map by a few K here and there. Even if you preset WB is a little wrong - or completely wrong. You make one adjustment and stamp it to every other image. Want a couple renderings? Make a couple of different adjustments and stamp them to every image with new versions in different albums. This takes all of 2 seconds vs going through and screwing with WB individually for every image in a sequence.
Better yet if you are a Nikon shooter you can pick a WB setting that you KNOW the exact correction for to match your NX2 interpretation and stamp that saved correction to every thing you shoot - or have a couple of them as starting points for different settings. Trust me on this - the usefulness of auto white balance is limited to a narrow range of shooting circumstances no matter how "good" the auto white balance is. Minor variations in WB shot to shot sucks.
Oh - Aperture noise reduction is not for any time of complex noise. It does not work anything like Noise Ninja or Nik Noise reduction software. If you are a noise nazi you will probably want to buy one of these tools. I happen to prefer Nik but rarely use it. I find that if I like an image I like it noise or not. Then again my noise is never really "bad" I sort of subconsciously compensate for the fact that I know it will have noise and put it where it doesn't matter - or at least maters less. I guess that comes from decades of shooting high speed color neg film where you had to do this.
These images are just some crap that I used to illustrate the point - This is a preset WB in a very tricky WB situation. They were shot on the worlds worst NEF interpretation in Aperture on a camera that has worse noise than anything you can buy today. The were shot at ISO 800 on a D2H. That camera was fantastic but at ISO 800 it was like a new camera cranked all the way up as far as the ISO can go - or worse. You may not like my choice of WB setting but that is not the point - you can apply ONE correction to every image in this sequence and be done.