Assigning buttons..so many options..Need advice.

[markj]

Still learning about my new D7000. I've come across assigning buttons to frequently used functions. It appears that there are
three different buttons that can used. 1) FN function button, 2) Preview button, and 3) the AE-L/AF-L button.
Could I solicit the help of any of you who have in fact assigned these buttons. And ask, what have you assigned the above #1
#2 and #3 buttons too, and possibly why.

 

[480sparky]

Function button: Access top item in MY MENU.

Preview button: Spot metering.

AE-L AF-L remains default.

 

[SCraig]

Function Button: Access top menu item in My Menu, and My Menu set up with things I change frequently.
Others: Default actions since I like them the way they are

 

[IgsEMT]

I don't remember the designation for the 1 & 2, but.... On my d700 one of them turns one the Live View and the other one turns on favorite menu. On my 300s one of them turns on the favorite menu and the other one is the preview. Similar configuration on the rest of the bodies.
AE/AF - on most of the bodies locks AF. Except on D90, which I use for home videos, AE/AF locks only exposure.

 

[Rhodes454]

Function Button - Spot meter. DoF Button - Viewfinder virtual horizon. AE-L / AF-L - Exposure lock only

 

[Mach0]

I use my AE-AF button for auto focus.

 

[zamanakhan]

I use my AE-AF button for auto focus.

Same, fn button for top menu which is cls and preview for the horizontal scale feature.