[robski]

I leave mind on auto 99.9% of the time - It tends to cause more of a problem when I forget to put it back. Auto seems to cope mainly with most daylight situations. It is only in extreme daylight conditions do I change it. e.g taking shots of blue bells in a shaded wood. The other time I will change is under artificial light, flash, fluorescent or tungsten.

With Auto you can get a colour shift which is difficult to fix in PS with a red flowers against green grass. I find you can't get a natural looking green.

If I know it is likely that the colours maybe wrong I carry a sheet of white paper so I can do a custom balance.

Or it will be one of the few times I shoot raw. I tend to save that for the nasty shots.