I have always used:
index finger - left click and middle scroll wheel
middle finger - right click.
But since installing a Rat 7 I'm experimenting with the following because the mouse seems too wide for 2 finger positioning
index finger - left click
middle finger - scroll wheel
ring finger - right click
p.s. I just found a previous post on this but I'm going to leave this one up since I'm not asking about gaming use specifically.
index finger - left click and middle scroll wheel
middle finger - right click.
But since installing a Rat 7 I'm experimenting with the following because the mouse seems too wide for 2 finger positioning
index finger - left click
middle finger - scroll wheel
ring finger - right click
p.s. I just found a previous post on this but I'm going to leave this one up since I'm not asking about gaming use specifically.