So I was investigating some things with my AF system that I never bothered to learn (regretfully now that I know a few things I was assuming incorrectly). It got me thinking about all the other features I don't take advantage of. When I first got my D700 I used the enhanced buttons reprogrammable features to do stupid shit, like turn on jpg+raw at a tap of a button incase I was shooting jpg and wanted to make sure I had a raw of the image... Now I am wondering what is the best use of the Fn and preview buttons? What type of program mapping do you to do your shutter button / ae-l and af-on buttons? I have taken a few tricks from a co-worker who is a big canon guy and arguably one of the best photographers I have ever met. I have changed my shutter to be Exposure only, I use AF-ON for focus, and I tend to find myself on Center weighted more than others. Meter, compose, focus, fire. I also have been using Spot a lot, and find matrix fluxates to much when on an assisted mode such as A or S, and due to some times wanting to make the shot and speed, I don't use M as much as others, unless I am working with flash or long exposure. I have found that even though the D700 has that nice knob for quick selection of metering modes, that some times I like to have the Fn button programmed to a hard stop meter. If I am out and about trying todo street photography I find I leave the camera on Matrix (ignore previous bitch) as I can get a good even scene exposure for the most part, focus, snap, and then to make sure my subject is exposed properly I hold Fn down and shoot again using the focus point / usually subject as my spot meter position. What do you guys do? What is your size recommendation for center weighted size? What type of AF mode do you keep it on? I have been trying different things. What AF tunes have you put in place? What AF mode (M,S,C) do you find yourself using most? Any hacks or clever tricks? What are you Preview/Fn/AE/Shutter etc assigned to.