Azfar Mahmood sent the following Custom User Interface macro for AutoCAD, which he uses to set the SNAPSTYL standard to isometric before changing the isoplane with the F5 function key. When set, the macro checks to see which isometric plane the user is working in and adjusts the snap setting automatically to match.

["F5"]'SETVAR;SNAPSTYL;$M=$(IF,$(!=,$(GETVAR,SNAPSTYL),1),1);+
'SETVAR;SNAPISOPAIR;$(IF,$(=,$(GETVAR,SNAPISOPAIR),2),0,$(+,$(GETVAR,
SNAPISOPAIR),1))
 

NOTES FROM CADALYST TIP PATROL:
This tip helps to save a few keystrokes, which is the key to efficiency. Thanks, Azfar!